
Oass—flU* \ \p . 

Book *_£i2 

Copyright^ L_ 



COPYRIGHT DEPOSIT. 



The Theory and Practice 



OF 



INFANT FEEDING 

With Notes on Development 



HENRY DWIGHT CHAPIN, A.M., M.D. 

Professor of Diseases of Children at the New York Post-Graduate Medical 

School and Hospital ; Attending Physician to the Post-Graduate, 

Willard Parker and Riverside Hospitals ; Consulting 

Physician to the Randall's Island Hospital 

and to St. Agnes Hospital, White 

Plains. 



CbirD B&ition, IRevisefc 



WITH NUMEROUS ILLUSTRATIONS 



NEW YORK 

WILLIAM WOOD AND COMPANY 

MDCCCCIX 



4- 






,>V ^ 



LIBRARY Of CONGRESS 
Two Cocies Received 

FEB 25 iyoy 

Copyright Entry 

CLASS ck. XXc, No, 

COPY 8. 



Copyright, 1909, 
By WILLIAM WOOD AND COMPANY 



tEo mi? 

FATHER AND MOTHER 

this volume is 

affectionately dedicated 



PREFACE TO THIRD EDITION. 



SINCE the second edition of this book was published 
much advance has been made in the science and art 
of infant feeding. It has become recognized that there is 
vastly more to artificial infant feeding than adjusting the 
quantitative differences between cow's milk and breast 
milk and that a new system of presenting the subject was 
necessary. 

Instead of making the superficial chemical composition 
of mother's milk the starting point* and striving to make 
an artificial human milk, as has been the case, it is more 
and more coming to be seen that the infant is subject to 
the general laws of animal life and that often these may 
be conformed to in a number of apparently different 
ways. 

Methods formerly condemned as unscientific, although 
they gave good results, are now seen to be in strict accord- 
ance with natural biological laws, while some procedures 
formerly taught as scientific have been shown to be the 
reverse. 

The chapters on practical feeding have been rewritten 
and broadened in this edition and sections on the princi- 
ple of top milks and the standardization of gruels have 
been added. 

It is gratifying to the author to feel that his efforts in 



vi PREFACE TO THIRD EDITION. 

treating infant feeding from the standpoint of biology 
have been recognized as of value in placing this impor- 
tant subject in line with general scientific development. 
Henry Dwight Chapin, M.D. 

February i, 1909. 



PREFACE TO SECOND EDITION. 



WHEN the first edition of this book was issued it 
was thought that artificial infant feeding could not 
advance much beyond its position at that time, unless the 
scope of study was broadened. The correct basis of the sci- 
ence of artificial infant feeding was then thought by many 
to be an adjustment of the quantitative differences of cow's 
milk and breast milk, and the alteration of the reaction of 
cow's milk to litmus paper by the addition of lime water 
or bicarbonate of sodium. A purely chemical basis was 
sought to be established. 

The author has never felt that this was a correct view 
of the subject, and, while accepting all that was an ad- 
vance, has thought that the suitability of a food for infants 
was not a matter of its chemical composition alone. It is 
gratifying to find that the most experienced investigators 
of the problems of animal nutrition have adopted this view 
with regard to the feeding of all species of animals, and 
that adaptation of the food to the particular species of 
animal according to its digestive apparatus is a recognized 
first principle of feeding. 

Since the first edition appeared, much work has been 
done with modern and improved methods in the compara- 
tive chemical examination of breast milk and cow's milk, 
with the result that many of their supposed differences 



viii PREFACE TO SECOND EDITION. 

have disappeared. The supposed distinctive difference 
of breast milk being alkaline and cow's milk acid in re- 
action, has been shown to be non-existent and due to the 
use of improper and unsuitable methods of determining 
the reaction. So this supposed fundamental difference 
proves to be of little significance and has lost its import- 
ance. 

Very important discoveries pertaining to cow's milk 
have recently been made, among which are some of the 
changes that take place in the digestion of milk and the 
effect of the addition of alkalies on the digestion of milk, 
all of which tends to make clearer the physiology of milk 
and the true principles of artificial infant feeding. 

The book has been carefully revised and some por- 
tions have been re-written and extended, and it is hoped 
that the second edition will more clearly than the first 
show what a peculiar and distinct position artificial infant 
feeding holds in the subject of dietetics. 

Henry Dwight Chapin, M.D. 

51 West Fifty-First Street, New York, 
June, 1904. 



PREFACE. 



THE great and increasing importance the subject of 
artificial infant feeding is assuming in all classes of 
society has led the author to believe there might be a 
field for a work on this subject that, instead of laying 
down rules and formulas for preparing food supposed to 
be suitable for infants of different ages, aimed rather to 
show the fundamental principles of growth, nutrition, 
and digestion during infancy, and then leave it to the 
physician to apply these principles. The discovery that 
the law of conservation of energy applies to animal life 
has made the nutrition of adults almost an exact science. 
In infant feeding there are other problems than mere 
nutrition that must be considered. The great mass of 
literature on infant feeding that has appeared within the 
past few years has been devoted in the most part toward 
producing a substitute food that should chemically ap- 
proximate human milk. In this book the special func- 
tion of milk in developing the digestive tract of the 
young animal is treated, the author believes, for the first 
time, and it is more than likely that further study along 
this line may necessitate greater or less modification of 
the conclusions here drawn. 



x PREFACE. 

American authorities on milk have been followed be- 
cause the conditions under which milk is produced and 
marketed in America are so different from those of Europe 
that many statements found in European medical jour- 
nals concerning milk supplies must be inapplicable to the 
work of a majority of American physicians, and besides, 
the greatest advances in dairying and knowledge of the 
chemistry of milk have been made in America. 

In the Appendix will be found a list of works and 
articles from which data have been drawn. The material 
of the book has been divided into four parts, each being 
as complete in itself as the subject will allow. By a 
system of cross references it is aimed to bring the prin- 
ciples involved and their application in close connection. 

The author wishes to acknowledge his indebtedness 
to Profs. W. A. Henry, S. M. Babcock, and F. W. 
Woll, and Major H. E. Alvord for valuable information; 
to Professor H. W. Conn for the chapter on Bacterio- 
logical Examination of Milk; to Dr. Hrdlika for making 
anthropological measurements, assisted by Dr. Pisek, and 
to Dr. Pisek for securing the photographs of infants. 
The thanks of the author are also extended to the pub- 
lishers for courtesies rendered during the preparation of 

the volume. 

Henry Dwight Chapin. 

August i, 1902. 



CONTENTS. 



PART I. 
UNDERLYING PRINCIPLES OF NUTRITION. 

CHAPTER I. 

PAGE 

General Introduction i 

CHAPTER II. 
How to Approach the Subject of Infant Feeding, .... 6 

CHAPTER III. 
Animal Cell— Its Constituents — Growth a Process of Cell Division — 
Young Animal Rudiment of Parent, 10 

CHAPTER IV. 
Object and Processes of Digestion — Mechanism and Comparisons of 
Digestive Tracts 16 

CHAPTER V. 
Broad Classification of Food into Protein, Fat, Carbohydrates, Min- 
eral Matter, and Water 25 

CHAPTER VI. 
The Chemical Processes of Digestion — Comparative Digestion and 

Absorption in Different Animals, 29. 

CHAPTER VII. 
Metabolism and Excretion, . 36 

CHAPTER VIII. 
Comparison of the Milk of Different Animals. Chemical and Physio- 
logical Differences 43 

CHAPTER IX. 
Summary, 59 



xii CONTENTS. 

PART II. 
RAW FOOD MATERIALS. 

PAGE 

CHAPTER X. 
Cow's Milk 63 

CHAPTER XI. 
Bacteriology of Milk, S6 

CHAPTER XII. 
Preservation of Milk, IOO 

CHAPTER XIII. 
Market Milk IIO 

CHAPTER XIV. 
Methods of Testing Milk i 33 

CHAPTER XV. 
Bacteriological Examination of Milk, . . . . . . . 143 

CHAPTER XVI. 
Cereals and Vegetable Foods, 170 

CHAPTER XVII. 
Proprietary Infant Foods, 179 

CHAPTER XVIII. 
Meats and Eggs, 183 



PART III. 
PRACTICAL FEEDING. 

CHAPTER XIX. 
Breast Feeding — Diet and Care of Mother — Elimination of Drugs in 
Milk — Care of Nipples — Contraindications — Menstruation — Preg- 
nancy — Wet-Nursing — Weaning and Mixed Feeding, . . . 195 

CHAPTER XX. 
Methods of Selecting Food for Adults not Applicable to Infants— Nu- 
trition and Development of the Digestive Tract must be Consid- 
ered Together, 206 

CHAPTER XXI. 
General Ingredients of Infant's Food, 218 



CONTENTS. xiii 

PAGE 

CHAPTER XXII. 
Preparation of Food, . . . . . . . . . .250 

CHAPTER XXIII. 
Food for Difficult Cases and for Temporary Use, ...... 267 

CHAPTER XXIV. 
Feeding by Gavage — Nasal Feeding — Rectal Feeding — Feeding Pre- 
mature Infants, 281 

CHAPTER XXV. 
Constipation, 2S8 

CHAPTER XXVI. 
Summer Diarrhoea, 293 

CHAPTER XXVII. 
Diet During Second Year 303 



PART IV. 
GROWTH AND DEVELOPMENT OF INFANTS. 

CHAPTER XXVIII. 
Growth and Development of Infants 311 

CHAPTER XXIX. 
Methods and Results of Measuring Normal Infants 3 2 4 

CHAPTER XXX. 
Growth of Head 33 2 

References, 341 

Index • 345 



PART I. 



CHAPTER I. 
GENERAL INTRODUCTION. 

Two controlling factors are present in all life— hered- 
ity and environment. At the birth of the individual the 
first has done its best or worst and cannot be reckoned 
with in the sense of being influenced. Its activity has 
been through long reaches of past time, and the laws of 
its operation are but imperfectly understood. The ques- 
tion of environment, being of the present and to a certain 
extent possible of control, assumes the greatest impor- 
tance. While from a purely biologic standpoint heredity 
may appear to be the most important influence, yet in the 
scheme of evolution the higher the animal the more im- 
portant becomes environment. This is specially empha- 
sized in man by the prolongation of the period of infancy. 
John Fiske was the first to elaborate this fruitful view of 
one of the fundamental laws of higher evolution, that not 
only throws a strong light on the methods of evolution, 
but lays the greatest importance on the period of infancy 
as influencing the future development and usefulness of 
the animal. This long period of helpless infancy is a time 
of extreme plasticity, when the career of the individual 
is no longer predetermined by the career of its ancestor. 
One generation of the lower animals is almost an exact 
reproduction of tin; preceding one. The young animal is 
born pretty fully formed, and can lookout for itself almost 



2 INFANT FEEDING. 

from the beginning, independently of the parent. The 
longer the infancy of an animal becomes, the greater the 
period of its teachability, and a slow growth means an 
increase in capacity for development and all the higher 
prerogatives. Thus the higher apes have a helpless baby- 
hood, when for two or three months they are unable to 
feed themselves or move about independently of the pa- 
rent. The human infant is distinguished from the high- 
est of the lower animals by the very long duration of help- 
less infancy and the marked increase in the size of the 
brain, and particularly in the extent of its surface. 
There is here a great increase in the size and complexity 
of brain organization that takes place largely after birth. 
Accompanying the rapid growth of the nervous system 
is that of the skeleton and various visceral organs. Dur- 
ing the first two years of life the brain not only doubles 
in weight, but increases marvellously in its convolutions 
and complexity. The infinite distance between man and 
the lower animals consists in the fact that in the former 
natural selection confines itself principally to the surface 
of the brain, and requires a long period of helpless infancy 
for this highly plastic work to be properly started and 
developed. Inherited tendencies are there, but the proper 
environment counts for much in this work so potent in 
future possibilities. It is evident that, correlated with his 
long period of helpless infancy, there must be a time of 
maternal care and watchfulness, if the race is to exist in 
health and vigor. Knowledge is required as well as care, 
for mistakes made at this time can never be completely 
corrected. The first few years of life are, biologically 
speaking, the most important ones we live. The begin- 



GENERAL INTRODUCTION. 3 

ning organism has at this time stamped on it the possi- 
bilities of future vigorous life or of early degeneration and 
decay. Hence a careful study and understanding of all 
the phases of infancy are of the greatest importance alike 
to physicians and parents. At a period of such rapid 
growth and development, it is evident that proper nutri- 
tion must play the leading part. All competent observers 
are agreed that the best nourishment for a baby naturally 
comes from its own mother. Unfortunately a large num- 
ber of mothers, from physical or social causes, are unable 
to give this proper nutriment. It appears to be one of 
the penalties of modern civilization that an increasing 
number of women cannot or will not nurse their offspring. 
Hence it is that in recent years a large amount of study 
and labor has been expended upon substitute infant feed- 
ing. Great advances have been made, but it must be 
confessed that the results are not always proportionate to 
the labor expended. The tendency appears to be to a 
greater degree of complexity and elaborateness than the 
average practitioner and mother can understand or ap- 
ply. Hence discouragement is apt to follow, and a return 
to old and haphazard methods if the immediate results 
are fairly satisfactory. Proprietary infant foods also pro- 
fit by this feeling of confusion, as they often agree with 
the baby for the time being, although not containing the 
proper ingredients for healthy growth and nutrition. 

The effort to place the food principles of milk in their 
proper ratio has led to " percentage feeding," which rep- 
resents a decided advance, but has been pushed to an 
extreme that is difficult, if not impossible, to apply. The 
author has long thought that some of the benefits of this 



4 INFANT FEEDING. 

method of feeding come more from the care and cleanli- 
ness with which the milk is handled than from the minute 
changes in the percentages that are often advised; in- 
deed, analysis sometimes shows that these fine changes 
are more on paper than in the ingredients of the milk. 
It is well to think in percentages and be as exact as pos- 
sible in feeding a baby, but the problem has not thus 
been completely solved, when we are putting the milk of 
one species of animal into the stomach of another spe- 
cies having a different digestive apparatus. 

The greatest problem in the life of any animal is that 
of securing sufficient food. All forms of animal life de- 
mand the same ultimate food elements, so that really 
their great diversification is along the lines of methods 
and organs provided by nature for securing and digesting 
food. While the outward forms of animals are apparent 
to every casual observer, their digestive systems, which 
are hidden, are as much diversified as their more appar- 
ent shapes, and are as much adapted for the digestion of 
a particular food as the outward organs are for securing 
it. Hence the milk of each type of animal must be stud- 
ied from the standpoint of its special adaptation to the 
digestive tract for which it is intended: a hard curding 
milk is intended for a polygastric digestive tract that can 
properly deal with it ; a soft curding milk for a monogas- 
tric digestive tract. These differences assume the great- 
est importance when the milk of one species of animal is 
fed to another species. This subject will be carefully 
considered in the present work, as it has a direct practical 
bearing upon successful infant feeding. While percen- 
tage feeding and the physical differences in the same 



GENERAL INTRODUCTION. 5 

ingredients in the milks of different species are of great 
importance, the preliminary question of how to get clean, 
fresh cow's milk is the fundamental one. Too little atten- 
tion has been given to this question in works on infant 
feeding. It will here be treated at some length and. in 
detail, as the observations of the author lead him to be- 
lieve that future advances in infant feeding must be prin- 
cipally along this line. In order to insist upon pure, clean 
milk, the physician must know how it is produced and 
insist upon proper conditions. It can easily be produced 
anywhere, if the details are properly carried out ; and this 
does not require an elaborate, expensive plant, as many 
believe. It calls for knowledge on the part of the physi- 
cian or sanitarian that can easily be conveyed to the farmer 
and dairyman. This is the first requisite in successful 
infant feeding:. 



CHAPTER II. 

HOW TO APPROACH THE SUBJECT OF 
INFANT FEEDING. 

i. Any one called on to feed an infant during the period 
it is normally nourished by its mother has a great respon- 
sibility thrust upon him and one not to be assumed lightly 
or without preparation. Too many are satisfied when 
something that is retained in the stomach and causes a 
gain in weight is found, no thought being given to whether 
the food contains material out of which healthy tissue can 
be formed. 

It has often been stated that an artificial food for in- 
fants should contain nothing that is not found in mother's 
milk, and that it should contain just what is found in 
mother's milk. To prove the suitability of various substi- 
tutes for mother's milk chemical analyses of both have 
been published, to show how closely the substitutes ap- 
proximate mother's milk. At first sight this seems a ra- 
tional procedure, but when it is remembered that there is 
no difference between a diamond and a piece of charcoal 
chemically, and that mixtures of butter, cheese, sugar, 
salts, and water, or of beef suet, raw beef, sugar, salts, 
and water, can be made which when analyzed by the usual 
methods will show the same composition as mother's 
milk, the fallacy of judging the suitability of a food for an 
infant, or for an adult for that matter, by its chemical 



HOW TO APPROACH INFANT FEEDING. 7 

analysis only will be apparent. Physiological chemistry 
has not advanced sufficiently to make it a safe guide by 
itself. 

In feeding an adult it is only necessary to furnish 
enough food to repair waste. In feeding an infant not 
only must waste be repaired, but material to build up new 
tissue must be supplied, or the infant cannot grow nor- 
mally. The whole future of the infant may depend on 
what kind of food is supplied it up to the time it can take 
table food. Then the danger of an insufficient supply of 
tissue-building food is not so great. 

The ability to resist disease depends largely on having 
the cells in which the vital processes take place plentiful 
in number and well nourished. These cells form a large 
portion of all the organs and tissues of the body, and if 
the material needed to build cells is not furnished in suffi- 
cient quantity, the gain in weight, if there is any, will be 
mostly fat and water. It does not follow that because a 
baby is fat that it is strong or healthy. The cells may be 
actually starving and so few in number that the body may 
be likened to a large showy house built with very light 
timbers, all ready to collapse under a slight strain (128). 

Not only must the food for an infant contain material 
from which cells may be built up, but the material must 
be in such a condition that the infant can digest it with- 
out undue effort. Furthermore the food must be cheap 
enough to be within the reach of all and easily prepared. 

Naturally the milk of the cow or of some other animal 
is suggested, but experience shows that these milks do 
not agree with infants generally, unless in some way 
changed or modified, the great difficulty being the inabil- 



8 INFANT FEEDING. 

ity of the infant to digest the elements of the milk of 
which cells are composed. Undoubtedly the milk of all 
animals contains the materials necessary to build up 
strong healthy cells and tissues, as no young animal 
thrives as well on anything else as it does on its mother's 
milk or on the milk of some other animal of the same 
species. At first thought it seems strange that the milk 
of one species of animal is not suitable for the young of 
another species ; but when the mode of living, and the 
digestive systems, rate of growth, and stage of develop- 
ment at birth of the different species are compared, it will 
be found that the milk of each animal is adapted to its own 
digestive system, rate of growth, and state of development ; 
also that the milk of the mother behaves in the young ani- 
mal's stomach very much as the food of the mother behaves 
in her stomach. The young animal is being educated to 
digest in the same manner as it will when it is grown. 
This subject will be gone into in detail in subsequent 
chapters, as it has been given very little or no considera- 
tion by writers on infant dietetics. 

Before there can be intelligent food prescribing there 
must be a knowledge of the substances needed to con- 
struct cells and keep them well nourished ; of the sources 
from which these substances may be obtained; of how 
they are transmitted to the cells through the blood stream 
after digestion and absorption ; of the nature of digestion 
and the digestive systems of different animals; of what 
changes take place in the food in the cells, and what be- 
comes of the waste products. Then only can feeding be 
taken up in a scientific manner. 

The problem of feeding infants in all classes of society 



HOW TO APPROACH INFANT FEEDING. 9 

calls for ability to produce a satisfactory food in a simple 
and inexpensive manner. This necessitates a knowledge 
of raw food materials, how they are produced, and the 
best means of preserving them from deterioration and in- 
fection by disease or other kinds of germs, and how these 
food materials, no matter what their source, may be best 
prepared for digestion by the infant. 

Before taking up methods of preparing food for in- 
fants, some space will be devoted to physiological chem- 
istry, physiology of young animals, comparison of the 
digestive systems and milks of various animals, the produc- 
tion of milk and other raw food products, and methods 
of analyzing and testing food materials. 



CHAPTER III. 

ANIMAL CELL— ITS CONSTITUENTS— GROWTH 
A PROCESS OF CELL DIVISION— YOUNG 
ANIMAL RUDIMENT OF PARENT. 

2. The unit of the animal organism is the cell. In 
the cells all the vital processes take place. They are the 
chemical laboratories of the body and are the ultimate 
destination of all the food that is digested. The lowest 
torms of animals are single-cell animals. These single- 
cell animals carry on all of the chemical processes that 
highly organized animals carry on. Every part of a sin- 
gle-cell animal can digest food, every part can breathe, 
every part can feel, and every part can think. All the 
faculties of an animal are bound up in one cell. The 
starting-point in the development of any animal is a sin- 
gle cell about one hundred and twenty-fifth of an inch in 
diameter. This cell divides and forms two cells, these 
divide, and so on. This increase in number of cells con- 
stitutes growth (Figs, i and 2). An organized animal, 
therefore, is a nation of cells, divided into many executive 
branches or organs. Certain organs are adapted for secur- 
ing food, others for digesting it, and others for throwing 
off waste products. Then there is the circulatory system 
that carries the necessary food to every cell in the body. 
All cells are in some way in communication with the 
blood supply and able to select from it food particularly 
suited to their needs. The cells of the bones select min- 
eral matter from the blood, other cells select other matter 



ANIMAL CELL. n 

that contains little earthy material. What none of the 
cells wants is excreted in the urine. It is absolutely be- 
yond human power to control the food requirements of a 




Fig. i. — Section of Ovum. (Jewett.) Shows the original cell or starting point of a.i animal. 

cell ; if it does not want particular food substances that 
are in the blood it will not take them, and if the food the 




Fig. 2.— Illustration of Cell Division or Growth. (Allen Thompson, after E. Van Beneden.) 

cell does want is not supplied, starvation of the cell is sure 
to result. Therefore a study of the cells is necessary to 
show their food requirements. 



12 INFANT FEEDING. 

The cells are so small that they cannot be examined 
except by the aid of a microscope, but as they make up 
a large part of the tissues of the body, a study of the tis- 
sues is practically a study of the cells. 

To the eye a piece of flesh consists of muscle, connec- 
tive tissue, cartilage, fat, and possibly mucous membrane, 
skin, blood-vessels, and nerves. 

The chief mass of these tissues, with the exception 
of water and fat, is called protein substance — the word pro- 
tein meaning "/ take the first place" All protein sub- 
stance contains carbon, hydrogen, oxygen, and nitrogen. 
Mostoi it contains in addition sulphur, and portions con- 
tain also phosphorus and iron. While the quantities of 
these elements vary somewhat, they are fairly constant in 
all of the tissues, but a chemical analysis of protein would 
not tell whether it came from skin, mucous membrane, or 
muscle. Other means of examining tissues had to be 
devised. These consist of extracting the tissues with 
various solvents. By this process various forms of pro- 
tein can be separated to a certain extent. The principal 
groups of protein substances so separated are: 

(i) Albumins and globulins, containing carbon, hy- 
drogen, oxygen, nitrogen, and sulphur. 

(2) Nucleo-albumins, containing carbon, hydrogen, 
nitrogen, oxygen, sulphur, and also phosphorus and iron. 

There are many forms of protein that are included in 
these divisions; for instance: 

White of egg is a mixture of albumin and globulin. 

Casein of milk (curd) is a nucleo-albumin. 

Another class of substances which contain carbon, 
hydrogen, oxygen, and nitrogen, but which are not protein 



ANIMAL CELL. 13 

substances, can be separated from animal tissues. These 
are called extractives or meat bases. The extracts of meat 
for making beef teas, sold in jars, which are claimed to 
represent ten to twenty times their weight 'of meat, are 
"extractives" (no). 

Fat, which is composed of carbon, hydrogen, and oxy- 
gen only ; lecithin, a kind of fat which contains also phos- 
phorus and nitrogen, found particularly in the brain and 
nerves ; and glycogen or animal starch, composed of car- 
bon, hydrogen, and oxygen, but in proportions different 
from those in fat, can also be separated from animal tissues. 

Mineral substances found in the tissues are thought to 
be combined with the protein substances and not to exist 
in a free state. 

3. In examining cells under a microscope, it is found 
that a certain portion of each cell — the nucleus — contains 
iron and phosphorus, and that the albumins and globulins 
which do not contain iron and phosphorus serve more as 
cell food than as cell builders. Lecithin and glycogen 
seem to be found in all cells. 

There can be no cell division or growth unless the 
nucleus of the cell first divides, and, as iron and phospho- 
rus are contituents of the nuclei of cells, there can be 
no cell growth unless food containing iron and phospho- 
rus is furnished. This has been proved by experiment. 

The materials necessary to build up cells must be 
found in eggs, as in an egg there is a single cell that be- 
gins to divide and ends by changing the contents of the 
shell into a live bird. The germinal cell is situated near 
the yolk, which is used up first, and then the white is 
drawn on. The yolk is rich in protein containing phos- 



i 4 INFANT FEEDING. 

phorus and iron, lecithin, fat, and mineral matter; while 
the white of the egg, which is about eighty-five per cent 
water, contains almost nothing that could be used to cre- 
ate cells (2). 

4. Up to the time an animal is born it is nourished by 
the blood stream of its mother, so all the elements for the 
developing animal must come originally from the moth- 
er's food. It would be expected that animals that feed 
on flesh, as cats and dogs, would be able to supply the 
materials needed to construct animal tissue ; but animals 
that feed exclusively on vegetable substances, as cows, 
sheep, and horses, also have no difficulty in constructing 
animal tissue. In fact, most of the meat supply of the 
world is the flesh of animals that live exclusively on vege- 
table substances, so the only conclusion is that the vege- 
table kingdom must be able to supply all the materials 
necessary to form animal tissue. 

Examination of hay, wheat, oats, barley, corn, beans, 
etc., shows them to consist principally of carbohydrates 
which contain only carbon, hydrogen, and oxygen. Cel- 
lulose, or the skeleton of plants, starch, and sugar are 
typical carbohydrates. Paper is made of the cellulose or 
cells of wood or straw. Potatoes and cereals contain large 
quantities of starch, and beets, sugar cane, and maple 
trees supply sugars. Starch and sugar are the stored-up 
food of plants. Vegetable tissues contain also small 
quantities of fat and lecithin and substances containing 
carbon, hydrogen, oxygen, nitrogen, and also sulphur, 
phosphorus, and iron, called vegetable protein. It is these 
substances that are converted into animal cells. Gluten 
or the sticky, stringy part of bread dough is a familiar 



ANIMAL CELL. 15 

form of vegetable protein. Chemically there is little dif- 
ference between gluten and lean meat. 

There is one important fact to be remembered : plants 
have the ability to take water, mineral matter and gases 
from the soil and air and combine them into proteid, 
fat, and carbohydrates. Animals cannot do this nor can 
they change fat and carbohydrates into proteid, but must 
take these three substances from the vegetable kingdom 
and elaborate them for their own particular uses; so a 
perfect food must contain proteid, fat, and carbohydrates in 
proportions suitable to the needs of each particular animal. 

It is evident that a cat or dog would starve if fed hay 
and grass, and that a horse or cow would not as a rule 
thrive on raw meat. Human beings feed on meat and 
vegetable substances, but not in the condition in which 
the lower animals eat them. They must be prepared by 
a cooking process before the human digestive apparatus 
can act to advantage. This forces the conclusion that the 
digestive system of each kind of animal must be particu- 
larly suited to its natural food. As young animals are 
miniatures or rudiments of their parents, their digestive 
systems must be in a general way like those of their pa- 
rents, so it would be natural to suppose the mother's milk 
would be particularly suited to the young animal's diges- 
tion, and that the milk of one kind of animal would not 
suit the young of another kind any more than the food of 
a cat would suit a cow or a horse. It is the substitution 
of some other milk that causes so much trouble in infant 
feeding. Chemistry has never been able to show why 
this substitution causes trouble. The answer has been 
hinted at, — different digestive systems. In the following 
chapters this important subject will be treated. 



CHAPTER IV. 

OBJECT AND PROCESSES OF DIGESTION- 
MECHANISM AND COMPARISONS OF DI- 
GESTIVE TRACTS. 

5. The object of digestion is to separate from the food 
that is eaten those portions that will serve as nutriment 
to the organism from those that are useless, and to put 
them into soluble, absorbable forms, so that the blood 
can carry them to every part of the body. 

The process of digestion consists of two distinct parts: 
(1) a mechanical part, and (2) a chemical part. The me- 
chanical part consists of grasping, tearing, chewing, or 
grinding the food ; the chemical part in the solvent action 
of the various digestive juices. 

The chemical changes that take place in a particular 
kind of food during digestion are practically the same in 
all forms of animal life, but the mechanism of digestive 
tracts varies greatly, and the kind of digestive juices that 
are secreted depends largely on the natural food of the 
animal. All animals must have protein in some form and 
all have digestive jriices that will digest it, while some 
animals have in addition digestive juices that will digest 
many other substances. A clog whose principal food is 
animal protein (meat) does not need a digestive juice that 
will soften hay or grass, and does not have it. A horse 
or cow needs a digestive juice that will soften and digest 



OBJECT AND PROCESSES OF DIGESTION. 17 

the fibres of hay or grass and liberate the vegetable protein 
they contain, when the same chemical change in the pro- 
tein takes place as in the dog's digestion. 

The discussion of what are the chemical changes that 
take place during digestion will be deferred until the 
mechanism of digestion has been briefly considered. 

6. To furnish a dog a pound of protein, about four 
pounds of lean meat would be fed, meat being about 
three-fourths water; to supply a horse a pound of protein, 
about thirty pounds of grass or sixteen pounds of dry hay 
would have to be fed. It is apparent that not only must 
the digestive system of a horse be relatively much larger 
than that of a dog, but much more complicated. 

It is a well-established fact that the more complicated 
the food the more complicated is the digestive tract. 

When a jelly fish comes in contact with its food it 
folds itself around it. When all the nutriment has been 
extracted it unfolds again. In a higher form of life the 
digestive cavity is permanent and is a straight tube. As- 
cending in the animal scale, the digestive tract becomes 
longer, curved, and separated into distinct parts that have 
special functions. Organs for grasping the food are pro- 
vided, and the character of the food and the digestive sys- 
tem of the animal can often, if not always, be known by 
a glance at these structures. 

Animals of prey have teeth adapted for tearing flesh 
and crushing bones. Their gullets are distensible, and 
they can swallow great pieces of meat and bones. Their 
digestive juices are particularly adapted for dissolving 
meat and even bone, and their digestive apparatus is short 
and simple. Their stomachs are capacious, being sixty 



[8 



INFANT FEEDING. 



to eighty per cent of the whole digestive tract, and the 

outlet to the intestine is small and kept closed until the 

food is liquefied, thus insuring thorough gastric digestion. 

Herbivorous animals, like the cow, goat, sheep, horse, 

and ass, have teeth for 
thoroughly chewing their 
food, and their gullets are 
small and non-distensible. 
With the cow, goat, 
and sheep, the food is first 
swallowed without chew- 
ing, and goes into the 
paunch or rumen, where it 
is softened very much as 
is the food in a bird's 
crop. The animal lies 
clown and at its leisure 
ruminates or rechews the 
food, which then goes into 
the fourth stomach — these 
animals have four stom- 
achs — where it is princi- 
pally digested, and then 
passes into the intestines 
through a small outlet, 
which allows only liquid or 
semi-liquid food to pass out. 
The stomach of the cow, goat, and sheep comprises 
about seventy per cent of the digestive tract. 

The horse and ass, which eat the same kind of food as 
the cow, have entirely different digestive systems. They 




Fig. 3.— Simple Digestive Tract of Carnivor- 
ous Animal (Dog) Stomach sixty to eighty 
per cent (After Bernard, modified.) 



OBJECT AND PROCESSES OF DIGESTION. 19 

chew their food once for all. Their stomachs comprise 
only eight to nine per cent of the digestive tract, and will 




Fig. 4.— Complicated Digestive Tract of Ox or Cow. Stomach seventy per cent. (Chauveau.) 

(1) Stomach. (2) Intestines. 

not hold more than one-third to one-half of a meal. The 
outlet to the intestine is large and open, and while the 



20 INFANT FEEDING. 

animal eats a meal the food passes directly into the intes- 
tine, which at the farther end is enormously developed, 
forming" about sixty per cent of the entire digestive tract. 
Young birds of prey are fed flesh, young worm-eating 
birds are supplied with worms, and young seed-eating 
birds with seeds. Here it is plain that the digestive sys- 




FlG. s 



Cow's Stomach. (Chauveau.) 



terns of young birds are very much the same as those of 
the parents. All young animals that are suckled are 
furnished milk, which is a fluid, while the parents' food 
is solid. This seems to be different than in the case of 
young birds which receive solid food, but in the stomachs 
of these young animals is found rennet, a substance that 
changes milk into a solid or semi-solid condition. Jun- 
ket is a familiar example of cow's milk turned into a solid. 



OBJECT AND PROCESSES OF DIGESTION. 21 

It has been stated that rennet seems to be a superfluous 
substance in the stomach, seeing that the milk is again 




Fig. 6.— Complicated Digestive Tract of Horse, (i) Stomach, eight to nine per cent. 
(2) Intestines, ninety-one to ninety-two per cent. (Chauveau) 

converted into a fluid by the digestive process, but that 
this is not so will be seen presently. 



22 INFANT FEEDING. 

While chemical analyses show all milks to be alike in 
containing the same ingredients, but in different propor- 
tions, milks differ in their behavior with rennet, and as 
chemical analyses give so little information as to the char- 
acter of the milk, chemists classify milks according to their 
behavior with rennet. It is found that cow's, goat's, and 
sheep's milk form solid curds when acted upon by rennet, 
which even when broken up into fine particles will readily 
unite again ; while horse's and ass' milk form a fluid jelly 
which will not become solid. Human milk seems to 
stand between these two types of milk. 

The greater part of the digestion of cows, goats, and 
sheep is performed in their stomachs, which, as stated be- 
fore, comprise about seventy per cent of their whole diges- 
tive system. In changing the milk of these animals into 
a solid that cannot easily leave the stomach, the rennet 
causes the digestion of the young animal to take place in 
its stomach, the same as in the case of the parent. 

The stomach of the horse or ass, being only eight or 
nine per cent of the digestive tract, will not hold enough 
food for a meal, and the outlet to the intestine is large, so 
the food can easily leave the stomach, which it does con- 
tinuously during a meal. The milk of the horse or ass 
does not form a solid lump, but a fluid jelly that can read- 
ily be forced into the intestine, which comprises ninety 
per cent of the digestive tract. Here again it is plain 
that the mother's milk is exactly suited physically to the 
digestive tract of the young animal, and that the process 
of digestion of the young animal is similar to that of the 
parent. 

In human beings, which eat meat and vegetable sub- 



OBJECT AND PROCESSES OF DIGESTION. 23 



stances, the digestive system is adapted for either class 
of food, but the food must be prepared for digestion by 
thorough chewing of meat and by cooking of vegetable 
substances, as no paunch or enlarged intestine is fur- 
nished where they may lie and soak preparatory to diges- 
tion. 

The human stomach, which comprises about twenty 
per cent of the digestive tract, is provided with a small 
outlet to prevent lumps passing 
into the intestine. This small 
outlet, teeth for dividing every 
kind of food, and salivary 
glands that secrete more fluid 
than the kidneys, show that 
the stomach was intended to 
receive soft, finely divided 
material which could easily 
pass into the intestine. If any 
proof of this conclusion was 
needed, the distress that is 
often brought on by hasty eat- 
ing and bolting great lumps of 
food would furnish it. 

Human milk does not form 
a solid lump or fluid jelly in 
the stomach, but a soft, finely 
divided mass. 

A whole book could be written showing instances of 
how nature adapts an animal to its surroundings and food, 
but from the few instances cited, which bear particularly 
on the feeding of young animals, it will be clear that, in 




Fig. 7. — Human Digestive Tract. 
Stomach, twenty per cent. (Leidy.) 



24 INFANT FEEDING. 

physical properties at least, there are different kinds of 
milk and that these differences are not freaks of nature 
or inexplicable, but are of the highest importance in de- 
veloping the y 07in g animal's digestive system; also that 
milks are not interchangeable from a digestive standpoint. 
These physiological comparisons throw a strong side light 
on the difficulties necessarily met with in utilizing the 
natural food of one species for the nutriment of another. 

In a future chapter the composition of milk will be dis- 
cussed and an attempt will be made to show that the dif- 
ference in composition of the milk of various animals 
is closely connected with the natural development and 
growth of the young animals. 

Before this subject is taken up, a little space will be 
devoted to the chemistry of food and digestion. 



CHAPTER V. 

BROAD CLASSIFICATION OF FOOD INTO PRO- 
TEIN, FAT, CARBOHYDRATES, MINERAL 
MATTER, AND WATER. 

7. Food is generally divided into four great classes: 

I. Protein, often called proteid or albuminoids. 

II. Fat. 

III. Carbohydrates. 

IV. Mineral matter or salts. In addition to these, 
water is a very important ingredient of food, as it enters 
into the composition of every part of the body, the bones 
even being over ten per cent water. There are many 
other important ingredients of food, but they are not gen- 
erally considered, as they are usually found with one of 
these four classes. The function of the protein of food 
is to build up muscular tissue; fats and carbohydrates 
are heat-producers, and mineral matter hardens the bones. 

I. Protein. The exact composition of protein or pro- 
teid has never been discovered, but it has been found that 
the different forms consist of: 

Carbon . 50. 6 -54. 5 per cent. 

Hydrogen 6. 5 - 7. 3 

Nitrogen (average about 16 per cent. ) 15.0 -17.6 

Sulphur o. 3 - 2.2 

Phosphorus o. 42- o. 85 

Oxygen 21.5 -23.5 

Iron is also found in some forms of protein. 
These figures in a general way represent the composi- 
tion of lean beef, pork, mutton, veal, fowl, fish, and of 



26 INFANT FEEDING. 

the total proteid of milk and eggs. Vegetable proteids 
seem to have about the same composition and chemical 
properties as animal proteids (4). 

II. Fats axe entirely different from proteids in compo- 
sition, being composed of about: 

Carbon 76. 5 per cent. 

Hydrogen 12.0 " 

Oxygen II. 5 

III. Carbohydrates form the chief portion of the dry- 
substance of the vegetable kingdom. 

The principal carbohydrates that are the natural food 
of animals are starch, found in potatoes and in nearly all 
the grains, and cellulose or the framework of plants. 

For human food, starch, in the form of cereals and 
bread ; glucose, found in grapes, raisins, molasses, and syr- 
up; cane sugar, or the familiar granulated sugar, which is 
found in sugar cane, beets, carrots, and the maple tree; 
and milk sugar, found in milk, are the principal carbohy- 
drates used. All these are composed of carbon, hydro- 
gen, and oxygen, there being two parts of hydrogen for 
each part of oxygen, which is the proportion in which 
these elements combine to form water, H,,0. Hence the 
carbon is hydrated, and the name carbohydrates. 

Cellulose consists of C 6 H 10 Oo or C 6 (HaO) 5 

Starch " " C 6 H 10 O 5 

Glucose " " C 6 H 12 6 

Cane sugar " " Ci 2 H 22 0n 

Milk sugar " " Ci 2 H 22 O u 

Chemically the only difference between all these car- 
bohydrates is the quantity of water (H 2 0) combined with 
the carbon. Physically there are great differences. Milk 
sugar and cane sugar, which have the same composition, 



BROAD CLASSIFICATION OF FOOD. 27 

are different from each other, as also are cellulose and 
starch. 

IV. Mineral matter is found in all forms of food, but 
it is hard to tell much about the state or combination in 
which it exists. 

8. In comparing the composition of proteids, fats, and 
carbohydrates, it will be noticed that the proteids are very 
complex and contain a fairly constant percentage of nitro- 
gen, which is not found at all in the fats and carbohy- 
drates. As proteid takes such a variety of forms, the 
only practical method of determining it quantitatively is 
to determine the quantity of nitrogen in the food and 
consider it sixteen per cent of the total proteid, as all pro- 
teid contains about sixteen per cent of nitrogen. The 
weight of proteid is found by multiplying the weight of 
the nitrogen by 6.25 (16 per cent X 6.25 = 100). 

It is not pretended that this method is exact, but it is 
the best that can be devised and answers all practical pur- 
poses. The lecithin, which is a kind of fat, is included 
with the proteid, as it contains nitrogen. 

Fats are determined by extracting the food with ether 
or other fat solvents. 

Carbohydrates cannot be determined directly. It is 
customary in most food analyses to determine proteid, 
fat, water, and mineral matter, add their weights together, 
and call the remainder carbohydrates. 

Mineral matter is determined by burning some of the 
food and weighing the ash. 

9- It is easy to see that a mere chemical analysis is not 
a safe guide in selecting a food for an animal, for a dog 
could not, on account of its simple digestive system, get 



28 



INFANT FEEDING. 



at the protein or fat of whole corn, for instance. It would 
starve with a stomach full of food that would nourish 
if it could only digest it ; after the corn was ground and 
cooked, the dog could digest it. This has led to a physi- 
ological test to see how much of a certain kind of food 
each species of animal can digest and assimilate. A meal 
is weighed, and the fat, proteid, carbohydrates, and mine- 
ral matter are determined. The animal is then given a 
capsule of lampblack and a little later is fed the meal ; be- 
fore the next meal another capsule of lampblack is given. 
The discharges from the bowels are collected, and what 
is between the two lampblack marks contains what was 
left undigested from the meal. This excrement is ana- 
lyzed and the digestibility of the meal determined. 

By this method some old theories of feeding have 
been completely upset, for it had been assumed that many 
foods were just what was needed because chemical analy- 
ses showed them to contain large quantities of nutri- 
tious substances. Digestion tests, however, showed that 
they were not digested, and so of course there was no ad- 
vantage in using the foods. A great many of these tests 
have been made on farm animals, and the following analy- 
sis will give an idea of the results: 





Water. 
Per cent. 


Ash. 
Per cent 


Protein. 
Per cent. 


Carbo- 
hydrates. 
Per cent. 


Fat 
Per cent. 


Timothy grass contained 

" " " digestible 

" hay " 

" " " digestible 


61.6 
61.6 
13-2 
13-2 

II. 
II. 

87.2 

87.2 


2 
4 

3 



1 
? 

4 
? 


? 

7 
> 


3-1 
2.28 
5-9 
2.89 

11. 8 
9.25 
3-6 
3.43 


32.OO 
23.7I 
74.OO 
43-72 
69.2 
48.34 
4-9 
4-7 


I.20 
■11 
2-5 
1-43 
5.0 


" " digestible 


4.18 

3-7 

3-7 


" " " digestible . . 



CHAPTER VI. 

THE CHEMICAL PROCESSES OF DIGESTION- 
COMPARATIVE DIGESTION AND ABSORP- 
TION IN DIFFERENT ANIMALS. 

io. Before any food that is eaten can be of use to the 
organism it must be chemically changed so that it can pass 
into the blood in suitable form. Each animal is fur- 
nished with digestive juices that produce the requisite 
changes in its natural food, but just what these changes 
are or how they take place is not thoroughly understood. 
The kind of digestive juice that is secreted depends 
largely on the food that is eaten. In the lower forms of 
animal life, as the jelly fish, which folds itself around its 
food, it is found that if animal food is taken, a digestive 
juice that will digest meat is secreted; if vegetable food 
is taken, a digestive juice that will digest vegetable sub- 
stances is secreted. As it was shown (6) that the more 
complex the food of an animal is, the more complex is its di- 
gestive system, so it will be found that the more complex 
the digestive system, the greater number of digestive 
juices there are secreted, each distinct portion of the di- 
gestive tract having a peculiar digestive juice particularly 
adapted to the condition of the food when it reaches it. 

In animals that live on flesh, a strong juice that dis- 
solves meat and even bone is found in the stomach. The 
food does not need to lie chewed or moistened before 



30 INFANT FEEDING. 

swallowing, and consequently little saliva is secreted. 
Here digestion is simple and the digestive tract is corre- 
spondingly simple (see Fig. 3). 

When it comes to herbivorous animals, like the cow, 
goat, and sheep, the digestive system becomes exceed- 
ingly complex (see Fig. 4). When hay is eaten it must 
be softened, and the ox secretes ten to twelve gallons of 
saliva a day; when grass is eaten, only one-third as much 
saliva is secreted. The food of these three animals goes 
to the paunch or rumen and soaks until the cellulose 
(crude paper) that envelops the nutritious portions of the 
food is softened and partly digested when the food is re- 
gurgitated and rechewed, and then passes into the true 
stomach where digestion principally takes place. In birds 
with crops and gizzards practically the same process is ob- 
served. The goat's fondness for bill posters and labels is 
not altogether the result of degeneration. It can digest 
part of the paper and all the flour paste on it. 

With the horse, mule, and ass, which eat the same 
kind of food as the cow, goat, and sheep, the order in 
which the digestive juices act is different. Their food is 
chewed with the saliva before it is swallowed, and the ex- 
posed portions that are easily digested are dissolved and 
the remainder of the food is passed into the caecum at the 
far end of the intestine (see Fig. 6), which holds as much 
as a cow's paunch, where the cellulose is partly dissolved, 
allowing the enclosed nutriment to be then digested. 
With cows, etc., digestion takes place principally at the 
beginning of the digestive tract ; with the horse and ass, 
at the end of it. 

It might be truthfully said that the great difference in 



CHEMICAL PROCESSES OF DIGESTION. 31 

the food of animals (for all must have protein, fat, carbo- 
hydrates, and mineral matter) lies in the fact that the food 
of herbivorous animals is wrapped up in cellulose (paper), 
while the food of carnivorous animals and human beings 
is not enclosed in cellulose. After this wrapping is re- 
moved from the food there is very little difference in the 
ability of different species of animals to produce the nec- 
essary chemical changes in the same food. Nature is 
very elastic on the food question, and in selecting a diet 
it is not so necessary to pay attention to fine points as to 
whether the food contains all the necessary elements and 
to their physical condition. Human beings cannot take 
their animal food in huge pieces as do carnivorous ani- 
mals, nor their vegetable food in the form herbivorous 
animals find convenient. Meat must be chewed and veg- 
etable substances cooked to break open the envelopes of 
cellulose. Each little starch grain has a coat of cellulose 
on it, upon which the human digestive juices have little 
action. Cooking starch by boiling or baking, as in bread, 
breaks these coats open and then the starch is readily 
digested (103, 105). 

11. The chemical changes in the food are brought 
about by enzymes found in the digestive juices. These en- 
zymes have never been isolated in a pure state, and what 
they are is not known. Their presence can be detected 
only by their action on food. There seems to be a par- 
ticular kind of enzyme for each kind of food. 

In human saliva is found ptyalin (diastase), which con- 
verts cooked starch into dextrin and maltose. In the gas- 
tric juice is found pepsin, which is secreted along with 
hydrochloric acid, which converts proteid into albumoses 



32 INFANT FEEDING. 

and peptones. Gastric juice has a strong solvent action 
on the connective materials that bind the muscular fibres 
together and causes meat to swell up and disintegrate into 
fine particles. 

The greater part of human digestion is performed in 
the intestine, so the action of the saliva in digesting the 
exposed starch and the action of the gastric juice in disin- 
tegrating the connective material of meat and vegetable 
proteids are preparatory to intestinal digestion and must 
be important. 

Fat, sugar, and starch are not acted upon by the gas- 
tric juice, and when present in excessive quantities in- 
terfere with its secretion. Fat and starch, by coating 
proteids, prevent the action of the gastric juice and throw 
the work of the stomach on to the intestines. Soaking 
bread in tea or coffee or washing down food with water 
does away with the action of the saliva on the starches, 
and frying food coats it with fat so that neither the saliva 
nor gastric juice can well act on it. Pork, on account of 
its containing so much fat, is particularly indigestible. 

In the intestine are found enzymes that will convert 
proteids into albumoses and peptones, but intestinal di- 
gestive juice does not cause proteid to swell up and disin- 
tegrate first, as does the gastric juice ; starch that escaped 
the action of the saliva is converted into dextrin, maltose, 
and dextrose ; cane sugar into dextrose and levulose ; and 
milk sugar into dextrose and galactose. As far as chem- 
istry shows, all these changes consist of the chemical ad- 
dition of water to the original proteid or carbohydrate. 
The actual changes have never been discovered. There 
are also found in the intestine enzymes that split and 



CHEMICAL PROCESSES OF DIGESTION. 33 

emulsify fats. Some of these enzymes are secreted by 
the pancreas, and others by glands of the intestines. 

These enzymes seem to act by contact, and to act best, 
the food must be finely divided and pulpy. Their diges- 
tive power is enormous. One part of crude invertase 
digested one hundred thousand times its weight of cane 
sugar, and was still active. 

12. The process of human digestion differs from that of 
the lower animals, in that the vegetable food must be pre- 
pared outside of the body to rupture the cellulose envel- 
opes, and the animal food chewed. The food then is tG 
be first treated with a starch-digesting fluid, the saliva, to 
expose the proteid; next with the gastric juice which dis- 
integrates proteid and reduces it to a pulpy jelly, and 
then only will the pylorus naturally open to allow food to 
pass into the intestine, where the greater part of the 
chemical changes in the food take place previous to ab- 
sorption. 

13. The secretion of the digestive juices is under the 
control of the nervous system. The thought of an appetiz- 
ing meal makes the mouth water, and the food is then 
pretty apt to be digested. Pleasant-tasting food taken 
into the mouth also excites the secretion of the digestive 
juices. 

The absorption of certain substances trom the diges- 
tive tract strongly excites the secretion of all the digestive 
juices. Among the substances that act as promoters of 
digestive secretion are the products of salivary digestion 
of starch (dextrin and maltose), and the extractives of 
meat (2). Substances which have the power of stimulating 
digestive secretion are also found in milk. 



34 INFANT FEEDING. 

14. The process of digestion is laborious at the best, 
one-sixth of the entire force of the organism being required 
to digest an average meal ; so an indigestible meal that re- 
quires prolonged digestive secretion, or has to be digested 
in the intestine without preparation in the mouth and 
stomach, causes great weariness. 

Excessive quantities of fat in the stomach retard not 
only the digestion of proteid by coating it, but also retard 
the secretion of the gastric juice and cause loss of appe- 
tite. Excessive quantities of sugar cause the stomach to 
secrete an unusually acid gastric juice, which interferes 
with digestion. These two facts should be remembered, 
as they have great practical value in infant feeding. 

Nervous shock or excitement interferes with normal 
digestive secretion. 

i5- Just how much of each of the digestive juices is 
secreted is not known, but an adult secretes more saliva 
than urine. There seems to be a continuous flow of di- 
gestive juice and absorption of digested food during the 
process of digestion. The process of absorption of pro- 
teid is not known. Some change takes place in the di- 
gested proteids during their passage through the walls of 
the digestive tract into the blood, for the products of pro- 
teid digestion are not found in the blood, and if injected 
into the blood are eliminated unchanged by the kidneys. 
Fats are emulsified and absorbed with little change. 

16. After the digested food has passed from the diges- 
tive tract into the blood, it must be carried to the cells in 
every part of the body. This does not take place sud- 
denly but gradually. Those portions of the digested food 
that are not immediately required are stored up for future 



CHEMICAL PROCESSES OF DIGESTION. 35 

use. The excess of carbohydrates is stored away in the 
muscles and liver in the form of glycogen, which is simi- 
lar in composition to starch; a great excess of carbohy- 
drates is eliminated by the kidneys or converted into fat. 
Excess of fat is stored away as fat. Proteids are not 
stored up in the adult, any excess being excreted, as will 
be explained in the next chapter. 

17. When an animal is not fed at all, the processes of 
life continue for a certain time, but there is a steady loss of 
weight. The glycogen stored in the liver disappears 
almost completely ; the stored-up fat also disappears, and 
all the muscles shrink away, and at last the animal dies. 

For a long time it was not known how the tissues fed 
upon themselves, but it has been recently discovered that 
in the blood there are enzymes that will digest glycogen 
or animal starch, converting it into dextrin, maltose, and 
dextrose, which is then carried to the portions of the 
body where it is most needed and again converted into 
glycogen. This is found to be the case even in the foe- 
tus. This same process must take place with fats and 
proteids, but the enzymes that produce the changes or 
what is the nature of the changes in the proteids have not 
been discovered. 

These enzymes that act in the system are called en- 
zymes of translocation, and have somewhat different 
modes of action from those of the digestive enzymes. 
They have been better studied in the vegetable kingdom, 
and their action can readily be appreciated by watching 
a potato sprout in a dark cellar or in the changing of a 
sprouting pea or a bean into root, stem, and a pair of 
leaves. 



CHAPTER VII. 
METABOLISM AND EXCRETION. 

18. The process by which the digested food is built up 
into living tissue, and the living tissue and food are re- 
duced to other and simpler dead forms, is called metabolism. 
This process is going on continually in the organism ; the 
object of food is to replace the loss caused by destructive 
metabolism and to build up new tissue. There can be no 
scientific feeding without a knowledge of the functions 
of each kind of food, how it is changed in the organism, 
what are its by-products, and how they are excreted. 

19. Fats and carbohydrates composed of carbon, hy- 
drogen, and oxygen are completely burned in the body by 
the inhaled oxygen of the air, into carbon dioxide and 
water, which are excreted principally through the lungs. 
These two food principles are mostly used as/^/to sup- 
ply the necessary heat to keep the body warm and fur- 
nish living force. 

Proteids can also act as fuel, but are incompletely 
burned in the body. The carbon dioxide produced in the 
metabolism of proteid is thrown off by the lungs, but the 
distinctive by-products of proteid metabolism are carried 
off by the urine in the form of urea, uric acid, phosphates, 
sulphates, and other salts ; so a study of the urine is very 
important. 

20. In practice, to determine the quantity of proteid 



METABOLISM -AND EXCRETION. 37 

that is being actually consumed in the body, it is only nec- 
essary to determine the quantity of nitrogen in the urine 
and multiply by 6.25 (8), which gives the weight of the pro- 
teid. It is a singular fact that in an adult animal there 
is what is called a nitrogenous equilibrium — that is, the 
amount of nitrogen eliminated equals the amount taken 
in as food. If the fats and carbohydrates are fed in ex- 
cess of the requirements of the body, they are generally 
stored up as fats, but with proteids it is different; an 
increase of proteid in the food produces an increase in 
the quantity of nitrogen in the urine, and in a few days 
the quantity of nitrogen excreted equals the quantity 
taken in as food. Possibly the excess of proteid is not all 
wasted, it may be partly changed into fat, but the only way 
an increase of proteid in the body can be brought about 
in an adult is by muscular activity, which increases the 
size of the muscles. Inactivity increases fat. Activity 
decreases fat and increases proteid up to a certain point. 
Growing animals that are laying on proteid are full of 
activity and playful, which they cease to be, as a rule, 
when fully grown. 

21. The amount of nitrogen that is eliminated in the 
urine depends on the animal's food; the urine of carnivor- 
ous animals is rich in nitrogen, while the urine of herbivor- 
ous animals is poor in nitrogen, which shows that in the 
flesh-eating animals large quantities of proteid are being 
consumed as fuel, while in the vegetable-eating animals, 
whose food is principally carbohydrates, small quantities 
of proteid are thus consumed. 

22. When animals arc starved they immediately com- 
mence to live on their own flesh and become carnivorous. 



38 INFANT FEEDING. 

Experiments made with metabolism during starvation 
show that the urine of the herbivorous animals becomes 
the same as that of the carnivorous animals in every way. 
The stock of carbohydrates (glycogen) that is stored up 
in the liver of all animals disappears after a few hours of 
starvation, and then the fat and proteids begin to disap- 
pear. 

During starvation the temperature of the animal re- 
mains about the same as in health, and the amount of ni- 
trogen in the urine, while less in quantity, is the same in 
proportion to the weight of the animal as it was in health 
in the case of carnivorous animals, and greatly in excess 
of the quantity in health in the case of herbivorous ani- 
mals whose diet is principally carbohydrates. Hence 
herbivorous animals do not stand starvation so well as the 
carnivorse. Metabolism is very active in young animals. 
Children die of starvation after about four or five days, 
while adults can often starve twenty days without lasting 
injury. 

Just before death from starvation the quantity of ni- 
trogen in the urine increases greatly; then the tempera- 
ture drops below normal, and the animal dies — the fire has 
gone out. Upon examination of the animal it is found 
that all the fat of the body has disappeared, even the bones 
having lost, and the proteid has been drawn on until the 
muscles of the heart are too weak to act. The increase 
of nitrogen in the urine just before death marked the time 
when all the fat had been used up and the proteid had to 
be drawn on exclusively for fuel. 

23 If a starving animal is fed carbohydrates or fats the 
quantity of nitrogen eliminated in the urine is greatly re- 



METABOLISM AND EXCRETION. 39 

duced and the animal loses weight less rapidly, but event- 
ually dies, as these food elements cannot be converted 
into proteid and there is always a certain consumption of 
proteid. Fats and carbohydrates are proteid sparers, car- 
bohydrates being more effective than fats. The knowl- 
edge of how to take advantage of this fact is of great 
value in the treatment of diarrhoea and fevers in which 
there is increased destruction of proteid with decreased 
elimination of urine, and in kidney affections in which 
the urea cannot be eliminated normally. 

24. If a healthy carnivorous animal is fed albumin 
(white of egg), which is a form of protein, it will die from 
starvation in about two months. Death from starvation 
will also follow if fats and carbohydrates are fed along with 
albumin, fibrin, or gelatin, which are all forms of protein. 
Attempts at separating different forms of protein for food 
purposes are not to be recommended, as grave errors in 
nutrition are likely to be the result. This much is 
known: the protein found in meat, whole milk, grass, 
and cereals, when given in the original state without 
attempts at separation into distinct classes or forms, will 
support life and produce good healthy tissue ; but just 
what part each form of protein plays in nutrition is not 
known. The form of fat and carbohydrate can be 
changed with little or no ill effect, but to assume if a 
form of food which contains sixteen per cent nitrogen 
and is digestible is given for protein that perfect nutrition 
will follow, is a policy that may lead to anaemia, rickets, 
or other forms of malnutrition. 

25. It will be seen from the foregoing that the functions 
of the fat and carbohydrates of the food are principally to 



4 o INFANT FEEDING. 

supply heat and living force, and those of the proteid to 
build the growing tissue and to repair waste ; also that 
when the waste in the tissue has been made good from 
the food, the excess of proteid in the food is burned and 
eliminated and not stored up as proteid in the adult. 
From a fuel standpoint, fat, carbohydrate, and proteids 
arc interchangeable in about these proportions: fat, 2% ; 
proteid, 1 ; carbohydrate, 1 ; but from a tissue-building 
standpoint they are not. This knowledge has led to the 
use in animal feeding of what is called a balanced diet ; that 
is, a diet which contains enough digestible fat and carbo- 
hydrates to furnish heat, and enough proteid to prevent a 
loss of proteid tissue. This point is determined by find- 
ing whether the nitrogen in the proteid of the food equals 
the nitrogen in the urine. The amount of proteid re- 
quired in the food depends largely on the animal. Wool- 
producing animals, as the sheep and goat, need more pro- 
teid than is actually used in the vital process in order to 
form the wool and hair; and milk-producing animals 
need more proteid in the food than those of the same 
species that are not secreting milk, as from three to four 
per cent of the milk is proteid. In an adult animal it is a 
waste to give much more nitrogen (proteid) in the food 
than is found in the urine during a period of fasting under 
the same conditions of living, as the only result is to 
throw extra work on the digestive and excretory systems 
with no gain to the organism. With children and young 
animals there should be more nitrogen (proteid) in the 
food than is found in the urine, as they need it to pro- 
duce new growth of tissue, and true growth consists of 
increasing the quantity of proteid in the body. 



METABOLISM AND EXCRETION. 41 

26. In artificial infant feeding the great difficulty lies in 
supplying proteid suitable to the infant's needs and diges- 
tion, and the great temptation is to cut it down in quantity 
or supply it in forms that are very easily digested. The 
result is that either not enough proteid to produce much 
healthy growth is furnished, or a large quantity of a form 
of proteid that cannot do more than retard the infant's 
consumption of its own tissue is given, and a poorly devel- 
oped child is often the result. This is an error that is 
almost sure to result from a diet based simply on a chem- 
ical analysis. 

27. During the process of digestion there is a greatly 
increased destructive metabolism of carbohydrates, fully 
fifteen per cent greater than in fasting under the same 
conditions, and also a slight increase in the destructive 
metabolism of proteid. Examination of the glands secret- 
ing the digestive juices shows that they absorb lymph, 
which is in some way changed into digestive juice and 
then secreted. Here is a source of slight loss of proteid 
during digestion, for this proteid matter is not all ab- 
sorbed, but goes in part to make up fecal matter. It is 
supposed by many that the faeces consist of undigested 
food. This is true to but a slight extent. Fecal matter 
consists almost wholly of secretions from the digestive 
tract. The intestines of a new-born infant contain fecal 
matter — meconium. A starving animal produces fecal 
matter similar to meconium, and a perfectly clean loop 
of the intestine will secrete feces. 

The character and quantity of the fecal matter de- 
pend largely on the food that is eaten. On an exclusive 
meat diet it is scanty, black, and pitch-like, and quite sim- 



42 INFANT FEEDING 

ilar to that from a starving animal, which is living on its 
own tissues. When fat is added to the food the fecal 
matter contains fat and is lighter in color. When vege- 
table substances are added to the diet the quantity of fae- 
ces increases and the color changes with the character of 
the food. The increased quantity consists in part of un- 
digested food, but principally of the increased secretions 
of the mucous membrane of the intestine, caused by the 
coarseness of the food and the mechanical action of the 
undigested portions. 

In health the color of the fecal matter depends on the 
kind of food. Bile pigments, calomel, and senna produce 
a green color, iron and bismuth a black, and rhubarb a 
yellow color. 

In normal digestion of human beings there should be 
little undigested food in the fecal matter, so an examina- 
tion of the stools is of the greatest importance in feeding 
infants — in fact, is absolutely essential to success (156). 



CHAPTER VIII. 

COMPARISON OF THE MILK OF DIFFERENT 
ANIMALS. CHEMICAL AND PHYSIOLOGI- 
CAL DIFFERENCES. 

28. The milk of all animals must contain the materials 
necessary for the nourishment of their young. Chemical 
examination of milks shows them all to agree in contain- 
ing water, fat, proteids or albuminoids, carbohydrates, and 
mineral matter. In addition to these ingredients, lecithin, 
cholesterin, citric acid, and other substances are found in 
varying proportions. 

The present knowledge of the chemical composition 
of milk can be best appreciated by the following quota- 
tions from recent high authorities upon the chemistry of 
milk: 

" Our present knowledge of the albuminoids of milk is 
far from complete, though much work has been done on 
the subject. This is due to the fact that it is extremely 
difficult to obtain these compounds in anything like a 
state of purity. . . . As there is no means of knowing when 
all the impurities have been eliminated, it is possible that 
we are yet unacquainted with the albuminoids of milk in 
a state of purity. This should not be forgotten during 
the study of the milk albuminoids. 

" In the albuminoids, the milks of different animals 
differ greatly. They may be divided broadly into two 



44 INFANT FEEDING. 

classes — those which give a curd, on the addition of an 
acid, and those which do not. In the first class are in- 
cluded the milk yielded by the cow, the goat, the gamoose, 
etc.; and in the second, human milk, that of the mare 
and the ass may be cited as examples. In the first 
class the curd is composed of casein, which is combined 
with phosphates of the alkaline earths; while in the 
second this is replaced by a similar albuminoid, which is 
not, however, combined with phosphates. It is possible 
that the difference between the albuminoids of the two 
classes is simply dependent on the presence or absence 
of the phosphates ; but the chemistry of these bodies is 
only in its infancy, and it would be premature to offer an 
opinion at the present time. Besides casein, or a similar 
body, there exists in all milks a second albuminoid called 
albumin ; this differs from casein by not being precipitated 
by acid, and by being coagulated by heat. Other albu- 
minoids have been described in milk, but many of them 
are only decomposition products of casein or albumin, 
which were formed during the process adopted for the 
removal of the other albuminoids. . . . 

"The sugar in milk is of a peculiar nature; that of 
cow's milk is called "lactose," or, more commonly, sugar 
of milk. It is generally assumed that all milks contain 
the same sugar, but of this there is some doubt. . . . 

" The sugar of the milk of the mare has the property 
of easily undergoing alcoholic fermentation, a property 
not possessed by lactose. According to the experiments 
of Carter and the author, the sugar of human milk is not 
identical with that of the milk of the cow" (Richmond). 

" The nitrogenous constituents of milk are very un- 



MILK OF DIFFERENT ANIMALS. 45 

stable compounds and their study presents many and great 
difficulties ; as a result we find that no two scientists who 
have made a special study of these compounds agree as to 
their properties, aside from those of casein and albumin, 
or their relation to the nitrogenous substances found else- 
. where in the animal body" . . . (Farrington and Woll). 

" The milk fat has rather variable specific gravity, 
which according to Bohr is 0.949-0.996 at + 15 C. The 
milk fat, which is obtained under the name of butter, 
consists in great part of the neutral fats palmitin, oleiu, 
and stearin. Besides these it contains, as triglycerides, 
myristic acid, small quantities of butyric acid and caproic 
acid, traces of caprylic acid, capric acid, lauric acid, and 
arachidic acids. . . . Milk fat also contains a small quan- 
tity of lecithin and cholesterin, also a yellow coloring 
matter. . . . 

" The milk plasma, or that fluid in which the fat 
globules are suspended, contains several albuminous 
bodies, casein, lactoglobulin, and lactalbumin, and a little 
opalisin, and two carbohydrates, of which only one, the 
milk sugar, is of great importance. The milk plasma also 
contains extractive bodies, traces of urea, creatin, crca- 
liuiu, hypoxanthin (?), lecithin, cholesterin, citric acid 
(Soxhlet and Henkel), and lastly also mineral bodies and 
gases" (Hammarstcn on cow's milk). 

It will be readily seen that an analysis of milk that 
took into consideration all its minor ingredients would be 
an exceedingly complex process and to a certain extent a 
needless one ; as a matter of fact there has never been a 
process of complete analysis of milk worked out. 

The usual method of analysis is to evaporate a sped- 



46 INFANT FEEDING. 

men of milk to dryness and call its weight total solids. 
What ether will extract from " total solids " is called fat, 
although the lecithin is also included. The total nitrogen 
in the milk is determined and its weight multiplied by 6.25 
(8) and called proteid. In this proteid is again included 
the lecithin as it contains a little nitrogen. A portion of 
the total solids is burned and the weight of the ash in the 
'milk is calculated as mineral matter. The weights of 
water, fat, proteid and mineral matter are added together 
and subtracted from the weight of the milk and the differ- 
ence called carbohydrates or sugar. This method is not 
exact, but answers all practical purposes in ordinary 
methods of calculating food values. 

Methods of determining casein and albumin in milk 
consist of adding acid which precipitates the casein but 
not the albumin ; the casein is removed by nitration and 
the nitrate is boiled, which precipitates albumin; the 
nitrogen in each is determined and multiplied by 6.25. 
When the weights of the casein and albumin so deter- 
mined are added together there is not as much total pro- 
teid as when the nitrogen in the whole milk is determined 
and multiplied by 6.25. „ . • 

According to A. Winter Blyth, an English 7 authority 
On food,. the casein of woman's, mare's, and ass' milk sep- 
arates only with great difficulty, and then not completely, 
upon the addition of acids. This may and probably does 
account for the small quantity of -casein reported in wom- 
an's milk by some chemists and the larger quantity ob- 
tained by others who employed different methods of 
analysis. This subject will be alluded to in another 
place (145). 



MILK OF DIFFERENT ANIMALS. 



47 



No method of quantitatively determining the sugar in 
milk has been devised. It is either determined "by dif- 
ference," or rotation of a ray of polarized light, or by the 
reduction of alkaline copper solution. The quantity of 
sugar present in a specimen of milk varies slightly with 
the method of determining it. 

29. The composition of any kind .of milk varies a 
great deal and it is customary to speak .of average milk. 
The composition of average milk is determined by adding 
together a great many analyses of milk and dividing the 
sum by the number of analyses. It may be that the re- 
sulting composition of milk may have never been actually 
met with. In speaking of woman's milk Hammarsten 
says : " Even after those differences are eliminated which 
depend on the imperfect analytical methods employed, 
the qjiantitative composition of woman's milk is variable 
to such an extent that it is impossible to give any average 
results " ; and of the milk of other animals, — " To illustrate 
the composition of the milk of . other animals the 'follow- 
ing figures* the compilation of -Koenig, are* given. As the 
milk of each kind of animal may have a variable com- 
position, 'these figures should be considered only as ex- 
amples of the composition of milk of varibus' kinds:" 

Salts. . 



Dog-. . 
Cat . . . 
Goat . 
Sheep. 
Cow . . 
Horse 
Ass. . . 



Wa.ter. 


Sdiids. 


Protelds. 


. Fat. 


Sugar. 


75-44 


24.56' 


9.9I , 


; 9-57 


3-*9 


81.63 


18.37 


9.68. , 


3-33 • 


4.91 


86.91 


I3.O9 


3.69 


4.09 


• 4-45 


.83.50 


16.50 


5-74 ! 


- 6.14 


3.96 


.87.17 


12.83 


3-55 ■ 


3.69 


4:88 


" g'0. 06 


9-94 


I.89 


1.09 


6.65 


90.00 


IO.00 


2.IO 


1.30 


6.30 



0.73 

.58. 

.66 
.66 
.71 

•3i 
• 30 



From the analytical figures just given it might readily 
be inferred that the great difference between milk of all 



4 8 



INFANT FEEDING. 



animals lay in the different percentages of water, proteids, 
fat, sugar, and salts, but a glance at the following analyses 
of cheeses made from milk with which all are familiar 
will show what a grave error such a conclusion w r ould be 
if applied to cheese: 



Ordinary cheese (made of cow's milk) . . 
Roquefort cheese (made of sheep's milk) 



27.20 
26.50 



32.05 
32.30 



36.60 
32.90 



4.15 
4-4 



30. Chemists have recognized that for anything but" 
comparison of potential food values, analyses of milk are 
valueless, and have classified milks according to their 
curding properties. 

All milks contain at least two forms of protein: casein, 
or, as it is called by some writers, caseinogen, and albumin, 
while some milks contain a large proportion of other 
forms of protein. 

Casein of cow's milk is easily precipitated by cold 
dilute acids, while albumin is not. The curds of sour 
milk consist principally of precipitated casein, If an 
alkali is added to neutralize the acidity of sour milk the 
casein assumes its original form. However, the precipi- 
tation, or curding of milk, by the addition of acids is not 
the physiological curding of milk. In the stomach of 
animals is found an enzyme — rennet — which clots milk 
very much as blood is clotted, and the character of this 
clot depends on the kind of milk that is used. 

31. The clotting of milk by rennet is an entirely differ- 
ent process from the precipitating of casein by acids or the 
souring of milk. Cow's milk is changed by rennet into a 
solid, which shrinks into a leathery, stringy mass that 



MILK OF DIFFERENT ANIMALS. 



49 



contains the fat of the milk embedded in the meshes of 
the curd. The albumin and other protein bodies and the 
sugar of the milk are squeezed out as " whey." Horse's 
'and ass' milk form a very soft, gelatinous curd with ren- 
net, and woman's milk forms finely divided curds. 

Even after the milks are classified according to their 
curding properties there are great differences in the com- 
position of the milks which need to be explained. Now, 
if instead of making the chemical analyses or curding 
properties of the milks the bases of comparison, the milks 
are classified according to the natural order of the animals 
producing them, the, reason for the wide differences in 
milks will appear, and each milk will be seen to be specially 
adapted in composition and curding properties to the rate 
of growth and digestive system of the young animal it 
was intended to nourish (Chapter IV.). 



Types of milk. 


'-< 


Curds: 


Is 

0. 






75 c 


$1 

PL, 






Dog. 

Sheep 
Goat. 
Cow. 

Mare. 
Ass. 


? 


75-44 

83.50 
36. 91 

87.17 

90.06 
90.00 

88.20 


9-57 

6.14 
4.09 
3-69 

1.09 
1.30 

3-3o 


3-19 
396 

4-45 
4.88 

6.65 
6.30 

6.80 


9.91 

5.74 
3-69 

3-55 

1.89 
2.10 

1.50 


0.73 

.66 
.86 
• 7i 

•31 

•30 

.20 


6-3 


(Stomach 60 to So per 
cent of digestive 
tract.) 

Ruminant \ 

Herbivorous i 

(Stomach 70 per cent 
of digestive tract.) 

Non-ruminant j 

Herbivorous / 

(Intestine 90 per cent 
of digestive tract.) 


Solid 

Solid 

Solid 

Gelatinous 
Gelatinous 

Flocculent 


6-8 
6-8 

8-12 

18 
18 

I4yrs. 


(Stomach 20 percent 
of digestive tract.) 





It should be remembered that these milks vary some- 
what in composition. (See 32 A, for separate analysis of 

proteids.) 

4 



50 INFANT FEEDING. 

It will be noticed that the milk of carnivorous animals 
is exceedingly rich in proteids ; that the milk of herbivor- 
ous animals, whose digestion is principally gastric, forms 
solid curds which cannot easily leave the stomach; that 
the milk of herbivorous animals, whose digestion is prin- 
cipally intestinal, forms gelatinous curds which easily 
leave the stomach and pass into the intestine ; and that 
woman's milk, which was intended for a digestive system 
in which the gastric digestion is more than that of the 
horse or ass, but not so great as that of the cow or goat, 
curds in flakes which stand between the other two types 
of curds. 

It is also remarkable how close to each other in type 
of composition the milks of different animals of the same 
class appear to be, and what a close relation there is be- 
tween the composition of the milk and the rate of growth 
of the animal. It may be pointed out that the fat and 
proteid in ewe's milk are much greater in quantity than 
in goat's milk and greater in goat's milk than in cow's 
milk. At first sight there appears to be no reason for 
this, but there is. Sheep produce wool and goats produce 
hair which are made up of protein substance and fat. 
Over forty per cent of the weight of raw wool is of a 
fatty nature and this fat is found not in the wool fibre 
alone but mostly on it. It is the familiar lanolin or wool fat. 
Hair does not have much fat on it and goat's milk does not 
contain anything like the same quantity of fat as sheep's 
milk. 

There is an apparent discrepancy between the com- 
position of cow's milk and mare's milk and the rate of 
development of their young. It must be remembered 



MILK OF DIFFERENT ANIMALS. 51 

that cows have been bred for years for the purpose of 
producing milk, and those animals that did not produce 
rich milk have been rejected. The ordinary common 
stock of cows does not produce milk containing fat 3.69, 
proteids 3.55 per cent, as shown in the analysis, but nearer 
fat three per cent and proteids three per cent. The dairy 
laws in most of the States call for only three per cent of fat 
in milk. Horses and asses have not been bred so as to 
produce rich milk as have cows. When these facts are 
taken into consideration, the apparent discrepancy dis- 
appears. 

32. One of the great differences between woman's milk 
and other milks, which is well known, but which is not 
shown in the analyses, is that woman's milk is richer in 
lecithin, which forms a large part of the brain and nerves. 
Within half an hour after birth a calf, lamb, kid, or colt can 
stand, and in a day or two runs around and sees, hears, 
and smells about as well as' its mother. In other words, it 
is born with a fully developed nervous system. A baby is 
very different in this respect, and it needs material for 
building up* its nervous system, and this is found abun- 
dantly in woman's milk, but not so much in other 
milks. 

32 A. In all milks there is greater or less quantity of 
soluble proteid generally called albumin, although not 
nearly all albumin, which is not retained in the curd, but 
which separates with the carbohydrates in the whey (31). 
This soluble proteid is readily absorbed from the digestive 
tract. It was shown that during digestion there was a slight 
increase in proteid and a large increase in carbohydrate 
metabolism (27). The first step in the digestion of milk, it 



52 INFANT FEEDING. 

will be seen, is a separation of easily absorbed proteid and 
carbohydrate, for which there is a great demand during 
digestion, from the casein and fat, which require more 
digestion and which are stored away in the growing ani- 
mal as fat and muscle; and in another place it will be 
shown that the fat of milk is mostly secreted at the latter 
part of a suckling or milking (36). 

32 B. The quantity and character of the soluble proteids 
of milk are of considerable interest in the comparison of 
milks. In 1897 Babcock and Russell discovered enzymes 
in milk which would digest its proteids in time if the 
bacteria present were destroyed by means other than heat, 
which destroyed the enzymes. To prove that the changes 
in the proteids of the milk were due to these enzymes, 
some very carefully conducted experiments and analyses 
were made. 

The casein and albumin were removed from milk by 
heating with acetic acid and filtering. The character of 
the remaining nitrogenous compounds was then carefully 
investigated, and they were considered to be principally 
albumoses and peptones (n). The milks were set aside, 
and from time to time portions were analyzed to detect the 
rapidity of the digestive process which was found to be 
slow, months being required before it was half completed. 

While the discovery of the presence of these enzymes 
in milk has no practical significance in infant feeding the 
analyses made in this connection are of the greatest 
value. 

In the following analyses by Babcock, Russell and 
Vivian only the cow's and goat's milk were the mixed 
secretion of several animals. In another place (38) will 



MILK OF DIFFERENT ANIMALS. 



53 



be found many complete analyses of the proteids of 
cow's milk. 



December 4th, 1897. 
December 4th, 1897. 
December 4th, 1897. 
December 4th, 1897. 
December 29th, 1897. 
December 13th, 1897. 
February 1st, 1898. . 

March 8th, 1898 

May 2d, 1898 

June 23d, 1898 

July 1st, 1S98 

February 21st, 1898. 

April 20th, 1898 

April 28th, 189S 

December 29th, 1898 
February 21st, 1898. 
March 8th, 1S98 



Sheep 

Sheep 

Sheep 

Sheep 

Sheep 

Human "| ? • ■ 
Human | 3 | . . 
Human I 3 2. 
Human j § * , . 
Human | 3 5j . . 
Human J 7 . . 

Goat 

Pig 

Pig 

Mare 

Burro 

Half-bred buffalo 
Cow 





. 1 


£c 




fc s 






J? 


£ 


0. 76 


0.09 


• 71 


. 10 


.60 


.10 


.76 


.09 


.80 


.10 


.28 


. 10 


.28 


.10 y 


.27 


.10 


.27 


.09 


.28 


.10 


.27 


.10 


.78 


.0.6 


.72 


• 17 


.70 


.16 


.28 


.09 


• 25 


.10 


.48 


.04 


• 51 


.04 



Y X6.25 = 
(by 
author) 





n 






Hi? ° 


S c 

Ec5 




IP 


4-75 


O.58 


4-43 


.62 


3-75 


.62 


4-75 


• Sb 


5.00 


.62 


1-75 


.62 


1-75 


.62 


1.68 


.62 


1.68 


.56 


i-75 


.62 


1.68 


.62 


4.S7 


•37 


4-5i 


1 06 


4-37 


1. 00 


1-75 


■ 56 


i-54 


.62 


3.00 


.25 


3.18 


•25 



It will not be difficult to see that the character of the 
proteids of milk cannot be told by the usual chemical 
analysis ; that w 7 ith improved methods of analyses different 
results are obtained, and that all young animals are not 
on a dead level when they are on a milk diet ; also that it 
would be irrational to expect by a simple adjustment of 
percentages of fat, sugar, and proteids to make milks 
interchangeable, even from a chemical standpoint. 

Having seen how little real help is to be derived from 
a chemical analysis of milk, it may prove interesting to 
glance at the place of milk in the animal economy. The 
material of which the young animal is composed is derived 
exclusively from the mother's body up to the lime it is 
able to eat and digest the same food as the mother eats. 
All animals are not alike in regard to the manner in which 



54 



INFANT FEEDING. 



the nourishment for the young animal is supplied. It 
may be all supplied at one time in the form of an egg, 
which the germinal cell turns into a more or less fully 




Pocket of Spiny Ant-Eater. ( Wiedersheim.) 



formed young animal, or it may be furnished gradually in 
small amounts. In the earliest stage of development of 
mammals the single cell is bathed in nutritive fluid ; as it 





Fig. 9.— Egg Laid and Hatched in Mammary Pocket shown in Fig. 8 and Resulting Foetus. Life 
size. (Photographed from specimens in the Zoological Collection of Columbia University.) 

grows more it either becomes attached to the uterine wall 
and develops a placenta and navel cord through which the 
nourishment is derived from the mother up to the time of 



MILK OF DIFFERENT ANIMALS. 



55 



birth ; or it is born in a poorly developed condition and 
grows fast to a teat, becoming a mammary foetus. In 
this case nearly the whole development is made on the 




Fig. ii.— Mammary Fostus of Kangaroo in Pouch. Life size. (Photograph of specimen in Zoo- 
logical Collection of Columbia University.) 

teat, the mother ejecting the nourishment into a specially 
adapted gullet until the young is strong enough to suck. 



5 6 INFANT FEEDING. 

Figs. 8 and 10 show an animal that lays eggs and suckles 
the young after hatching the eggs. 

Figs, ii and 12 show the mammary foetus adherent 
to the teats. 

At one time in the past the mammary foetus was com- 
mon, but is now becoming extinct. It is interesting in 
this connection only in showing that the infant during 
the nursing period should be looked upon as still being 




Fig. i2.-Young of Opossum Adherent to Teats. Half life size. (Photographed from specimens 
in the Zoological Collection of Columbia University.) 

physiologically attached to the mother, and that it is not 
naturally fitted for nourishment not derived from her 
body, as it is not fully formed. 

In the early foetal stages all animals are so much alike 
in all respects that it is practically impossible to determine 
one species from another species, as is shown by Fig. 13. 

The digestive tracts are alike at first and simple tubes,, 
but gradually develop into the more or less complex forms 



MILK OF DIFFERENT ANIMALS. 



57 



of the adult. Fig. 14 shows development of human di- 
gestive tract and Fig. 15 the stomachs of a number of 
mammals. 

The milk of the mother, by the curding of the casein 
in the stomach, develops the digestive tract of the young 





"U/ur 




Fig. 13.— Earl 



d Later Foetal Stages of Fish, Salamander, Tortoise, Chick Rabbit. (Haeckel.) 



animal. The caseins of milk differ according to the type 
of digestive tract. Caseins behave in a peculiar manner 
when acted upon by the digestive juices, which make 
them the necessary basis of the artificial infant food. In 
the section on practical feeding this behavior of casein is 
explained in detail. Milks, therefore, have important prop- 



5 8 INFANT FEEDING. 

erties other than simple food values, which cannot be de- 
termined by the chemist. 

They have physiological properties which should be 




Fig. ^.-Development of Human Digestive Tract. (Allen Thomson and Wiedersheim.) 




Fig 15 -Stomachs of Different Mammals. (Wiedersheim.) .4. dog; j5>, rat ; C, mouse ; D, weasel ; 
E, ruminant ; F, human; G, camel ; //, spiny ant-eater ; /, three-toed sloth. 

better understood and which are connected with the 
diversification of digestive tracts. 



CHAPTER IX. 

SUMMARY. 

33. In the preceding chapters it was shown: (1) That 
all animals are alike in the chemical processes that take 
place within their organisms during starvation, and that the 
administration of digestible fat, proteids, or carbohydrates 
singly produces the same result in all kinds of animals. 

(2) While chemically there seems to be no difference 
between the different forms of animal life, physiologically 
there are vast differences, and these differences seem 
to be closely related to the food supply, all the organs and 
parts of the body of a particular kind of animal being 
adapted to enable it to secure and digest its natural food. 

(3) In the case of young animals which take milk it was 
shown that not only does the milk of different species of 
animals contain practically the same food elements in 
varying proportions and forms suited to the needs of each 
particular species, but that the milks possess different 
curding properties that make them particularly suitable 
to their respective digestive tracts, and that the process 
and order of digestion in the young animal are practically 
the same as those of the parent. 

(4) It has also been shown that while the chemical 
composition of milks varies greatly, there is a type of com- 
position for each distinct class of animals, also that the 
variations within these types are considerable; but that 



60 SUMMARY. 

in spite of these variations, each distinct type of milk has 
certain physiological properties that do not vary with the 
change in chemical composition or concentration of the 
milk. For example, poor or diluted cow's milk has the 
same curding properties as the rich milk of cows. (5) 
That the selection of a food for any animal cannot safely 
be made upon a chemical analysis only, but by the aid of 
a digestive test. (6) That some forms of proteid, even 
when digested, will not produce a healthy tissue, and that 
there are certain combinations of the various food prin- 
ciples or elements that must be made to suit each class of 
animals. As the chemistry of the animal tissues, ingredi- 
ents of milk, and different foods is only in its infancy, and 
the functions of all the food elements are not thoroughly 
understood, it is useless to attack the problem of artificial 
infant feeding from tl e standpoint of chemistry alone, al- 
though a knowledge of food chemistry is of great assist- 
ance. What is needed is a knowledge of the substances 
that have proved to be able to support life and produce 
healthy tissue; how to combine and to adapt them to suit 
the needs and digestive system of the infant; the indica- 
tions of malnutrition and faulty digestion, and how to 
spare tissue waste in disease by an alteration of diet. 

In the following chapters the production and properties 
of raw food materials will be taken up and then the prac- 
tical problems of infant feeding. 



PART II 



CHAPTER X. 
COW'S MILK. 

34- Colostrum. — When the calf is born its digestive sys- 
tem has never been used and the cow's udder secretes 
a substance entirely different from normal milk, called 
colostrum, which seems to be designed to educate the calf's 
digestive system to digest food. Colostrum is composed 
of fat, sugar, proteids, mineral matter, and water, as is 
normal milk, but the character of the proteids and sugar 
is different from that of normal milk. The proteids of 
colostrum consist largely of albumins and globulins, and 
also albumoses and peptones, which are easily assimi- 
lated, and the sugar is said to be dextrose — the sugar 
found in the blood and not the milk sugar which is found 
in cow's milk. 

The character of the udder secretion gradually changes, 
the albumins and globulins being replaced by casein and 
the dextrose by milk sugar. The albumins and globulins 
of colostrum will coagulate upon boiling just as does the 
white of egg. To determine when the udder secretion 
has become normal milk it is boiled and if it does not 
coagulate it is considered fit to be used as milk. The 
time that elapses between the birth of the calf and the 
secretion of normal milk varies, sometimes being from 
five to seven days and again as long as twenty-one 
days. 



64 



INFANT FEEDING. 



The following analyses made at the Vermont Ex- 
perient Station will give an idea of the composition of 
colostrum : 



Total solids. 
Per cent. 



First milking 

Second milking 

Third milking 

Fourth milking 

Three weeks after calving. . 



19-37 
14-33 
12.98 

13. 02 

13-52 



Fat. 
Per cent. 



3-86 
2.92 

2.58 

3-71 
4.60 



Sugar. 
Per cent. 



2.40 
3.60 
4.16 

4.28 
5.00 



Casein and j 
albumin. 
Per cent 



ii- 44 
6.49 
5.01 
4- 7i 
3-34 



Ash. 
Per cent. 



I.67 
i-33 
1.23 
1.24 

.58 



35. Constituents of Coivs Milk. — In a broad way cow's 
milk is composed of fat, sugar, proteids, mineral matter, 
and water. Blood, pus, and epithelium may be present 
under certain conditions. The fat is not a single body 
but a mixture of various fats (28), which change somewhat 
in character, depending on the period of lactation and the 
character of the cow's food. Cotton seed fed to cows 
makes a hard milk fat; linseed meal makes a soft fat. 
The fat is suspended in the milk serum in fine globules, 
the size of which varies with the breed of cows and also 
in different portions of a milking (36). 

There are two carbohydrates in cow's milk, the prin- 
cipal one being lactose, the common milk sugar. 

The proteids of cow's milk as far as known are com- 
posed of casein (by some authors called caseinogen), albu- 
min, albumoses, peptones, and S torch's mucoid proteid, 
which has the property of swelling up under the action of 
alkalies (45). 

The mineral matter of milk is not thoroughly under- 
stood, but the following analysis by Richmond tells about 
all that is known of it. 

" The ash does not truly represent the mineral con- 



COW'S MILK. 65 

stituents of milk. The average composition of the ash 
of milk is: 

Per cent. 

Lime 20. 27 

Magnesia 2.80 

Potash 28. 71 

Soda 6. 67 

Phosphoric acid. 29. 33 

Chlorine 14. 00 

Carbonic acid .97 

Sulphuric acid Trace. 

Ferric oxide, etc , , . , . , .40 

103.15 
Less + CI..., , 3.15 

100.00 " 

Lecithin found dissolved in the fat, citric acid, urea, 
and cholesterin are minor constituents of cow's milk. 
Certain enzymes are also found in milk, but these have 
practically no importance except in the manufacture of 
various kinds of cheese. These enzymes are mentioned 
in another place (32). 

36. Composition of Cow's Milk. — The composition of 
cow's milk varies, greatly, and it is impossible to give a rep- 
resentative analysis that will do more than show what the 
average composition of milk would be during a long period 
if the cows gave the same milk each day and at each 
milking. This kind of analysis is useful only in showing 
the amount of food material cows produce during a stated 
period. 

One Cows Milk. — The milk of individual cows shows 
great and sudden variations in composition, and it is for 
tins reason that the mixed milk of a herd of cows is better 
for general use than one cow's milk. While there are 
great differences in composition between the mixed milks 
of different herds of cows, there are not apt to be gj'cat 
5 



56 



INFANT FEEDING. 



and sudden variations, and with care the milk can be kept 
very uniform in composition. 

The changes in composition in one cow's milk are 
caused by various influences, as sudden change of the 
character of the food, fright, unfamiliar surroundings, and 
irregular intervals between milkings. Gradual change in 
the character of the food, running from low proteid to 
high proteid and vice versa, low fat to high fat and vice 
versa, and high carbohydrates and low proteids cause no 
perceptible change in the composition of the milk. It 
is the opinion of all investigators that the quantity and 
quality of the milk depend on the cow, and that there is 
no method of feeding that will cause a particular cow to 
change the natural quality and quantity of milk secreted, 
except for a few days, when there will be a return to the 
normal of each cow. 

The following analyses of individual cow's milk show: 
(i) The variation in quantity of fat and size of fat globules 
in different portions of a milking — the solids not fat 
seem to change little; (2) the variations in composition 
and yield of milk during a lactation period; and (3) the 
effect of irregular hours of milking. These analyses are 
suggestive of changes and conditions affecting the secre- 
tion and composition of breast milk. 

(1) Fractional Milkings. Boussingault (quoted by 
Richmond) reports: 





First 
portion. 
Per cent. 


Second 
portion. 
Per cent. 


Third 
portion. 
Per cent. 


Fourth 
portion. 
Per cent. 


Fifth 
portion. 
Per cent. 


Sixth 
portion. 
Per cent. 


Total solids 


IO.47 
I.70 

S-77 


IO.75 
I.76 
S.99 


IO.85 
2. IO 

S-75 


II.23 
2.54 
8.69 


H.63 
3- M 
8.49 


12.67 
4.0S 
S-59 


Fat 







COW'S MILK. 



67 



Collier at the New York (Geneva) Experiment Station 
obtained the following figures: 



First Cow — 
First 
Second 
Third 
Fourth 
Fifth 
Sixth 
Seventh 
Eighth 
Ninth 
Tenth 
Eleventh 
Twelfth 
Thirteenth 



Fat. 
Per cent. 



pint 



0-3 
•3 



All mixed 19 



Second Cow — 
First pint , 
Second '* 
Third " , 
Fourth " 
Fifth •' . 
Sixth " , 
Seventh " , 
Eighth •• , 
Ninth '« , 
Tenth 



All mixed 2. 77 

Third Cow — 



First 

Second 

Third 

Fourth 

Fifth 

Sixth 

Seventh 

Eighth 

Ninth 

Tenth 

Eleventh 



pint 



Relative size fat 
globules. 

36 

44 

93 
108 

97 
133 
154 
174 
114 
147 
190 
194 
251 

129 



0.5 


128 


1. 1 


204 


1.3 


173 


1.8 


137 


2.4 


342 


3-4 


221 


4-45 


340 


5.o 


347 


5.0 


270 


6.25 


365 



SI8 



i-55 


3S7 


3-05 


367 


3-30 


3S8 


4.00 


476 


4.40 


323 


5.00 


575 


6.10 


565 


6.50 


333 


7.00 


722 


S.05 


725 


9.40 


644 



All mixed 6.00 



C59 



68 



INFANT FEEDING. 



(2) Variations in composition and yield during a lac- 
tation period, reported by Farrington. 

Holstein Cow — 278 Samples. 



Daily yield in pounds. 

Highest 

Lowest 

Average 



37-0 

1.7 

21.7 



Solids not fats — per cent. 

Highest 10.9 

Lowest 7.2 

8 times below 8.0 

24 " above 9.0 

Short Horn Cow— 428 Samples — Sudden Changes not Common 



Fat— per cent. 

Highest 6.6 

Lowest . . . ■. 1.5 

72 times below 3.0 

25 " above 4.5 



Proteids — per cent. 

Highest 4. 1 1 

Lowest 2.64 



Daily yield in pounds — 

Highest 26. 5 

Lowest 3.5 

Average 14.4 



Fat — per cent. 

Highest 7.9 

Lowest 2.5 

17 times below 3.0 

38 " above 4.5 



Proteids — per cent. 

Highest 3.89 

Lowest 2.92 



Solids not fat — per cent. 

Highest n. 3 

Lowest 7. 2 

1 1 times below 8.5 

7 " above 10.5 

Jersey Cow — 614 Samples — Sudden Changes Common. 
Daily yield in pounds — 

Highest 25.5 

Lowest i'.o 

Average 16.4 



Solids not fat — per cent. 

Highest 11. 7 

Lowest 7.6 

3 times below 8.0 



Fat — per cent. 

Highest 12.3 

Lowest 2.9 

5 times below 3.5 

25 " above 7.0 



Proteids — per cent. 

Highest 5.3 

Lowest 2.98 



24 " above 10. 5 

(3) Unequal Intervals between Milkings. The shorter 
the intervals between milkings the smaller will be the 
yield and the richer the milk. Long intervals cause large 
quantities of poor milk. It is for this reason that gener- 
ally in summer, morning milk is richer than night milk, 
and in winter, night milk is richer than morning milk. 



COW'S MILK. 



69 



Cows are milked the first thing in the morning and the 
last thing at night by most farmers. In summer the nights 
are about nine hours long, and in winter the days have 
about this same length. The following tests made at the 
Delaware Experiment Station illustrate these statements. 





Yield. 
Ounces. 


Fat. 
Per cent. 


Total solids. 
Per cent. 




154.6 
I5I.O 
184.O 
112. 5 


4-63 
4-74 
4-36 
5-32 


14.25 

14-37 
14.53 
15-36 






" 5 P.M 



Night milk. 
Fat— per cent. 



Morning milk. 
Fat — per cent. 



July 24th. . . . 
February 5th 



3.76 
4-56 



4.67 
3-53 



37- Curding of Milk.— -The curding of sour milk, so 
familiar to every one, consists of a precipitation of the 
casein by the lactic acid developed during the souring 
process. Upon neutralizing the acid with an alkali the 
casein goes back into 'its original condition. The curding 
of milk in the stomach is an entirely different process 
(6, 31). It is brought about by the action of rennet, which 
clots the casein very much as blood is clotted by the en- 
zyme thrombase which exists in the blood. This clotted 
casein is called paracasein. The milk forms a solid jelly 
when acted on by rennet, which soon begins to contract, 
and a greenish-yellow fluid known as whey exudes, which 
contains a small amount of fat, the soluble proteids, the 
sugars, and part of the mineral matter of the milk. A 
slightly acid condition of the milk greatly favors the 
curding or clotting of milk by rennet. When the condi- 



70 INFANT FEEDING. 

tions are right the curd shrinks rapidly and forms a tough, 
semi-fibrous mass that contains the fat in its meshes. If 
this curd is broken into small particles they readily unite 
again into a solid mass if allowed to remain in contact 
with each other; but if the particles are agitated for a few 
moments a skin or membrane forms on each, which pre- 
vents their uniting. The casein in this form of curd is 
changed chemically and cannot be put back into its origi- 
nal form by any known process. The rennet and acid 
curds are a mixture of paracasein and acid depending on 
which acid was present. 

It is often stated that cow's milk has an acid reaction 
when it leaves the cow or in its fresh state. Acidity of 
milk is never estimated directly, but by the use of some 
color indicator. Milk that is neutral to litmus is usually 
quite acid to phenolphthalein ; but it is thought that this 
lis not true acidity, but the effect of the salts and casein 
found in the milk. The acidity of milk that aids the 
action of rennet is true acidity and is shown by litmus. 
An interesting proof that the acidity to phenolphthalein 
is not true acidity has been shown by Babcock, Russell, 
Vivian, and Hastings. They found that pepsin, which 
digests proteid only in the presence of acid, would not at- 
tack the proteids of milk that was acid to phenolphthalein 
until 0.2 per cent HC1 was added, also that boiled milk 
would not coagulate with rennet ; but it did so at once, as 
soon as acidified (82). 

It is important that the difference between the acid 
curds and rennet curds of milk should be understood. 
Much confusion has arisen because this difference was 



COW'S MILK. 71 

not considered. Series of tests with acid curds have been 
used as bases for preparing cow's milk for infant feeding, 
but as, under physiological or rennet curding, entirely 
different results are obtained, these teachings, based on 
acid curding of milk, have been abandoned. 

A clear conception of the difference between the acid 
curding (precipitation of casein) and the rennet curding 
(clotting of cow's milk) can be quickly obtained by per- 
forming the following experiments, preferably in small 
evaporating dishes : 

1 st. Dissolve 1 c.c. of hydrochloric acid in 99 c.c. of 
water. Add this gradually to 60 c.c. of fresh milk that is 
neutral or only faintly acid to litmus paper until a precipi- 
tate forms, and note how many cubic centimetres of the 
dilute acid were required to precipitate the casein. This 
is similar to the sour milk curds. 

2d. To 60 c.c. of the same milk add first 1 or 2 c.c. of a 
solution of rennet made from the commercial liquid ren- 
net or from the junket tablets sold in all grocery stores — 
one tablet to 30 c.c. water — and then add the dilute hy- 
drochloric acid until a precipitate forms, and note how 
many cubic centimetres of the dilute acid were required 
to cause the precipitate to form. Much less acid will be 
required than when no rennet is used. Now bring the 
curded milk to blood heat and the rennet curd will begin 
to shrink and after a Jew minutes will become tough and 
fibrous so that it can be handled without breaking. This 
curd is a mixture of paracasein and acid. 

If this experiment is performed, using 20 c.c. of milk 
and 40 c.c. of water, the shrinking is more pronounced. 



72 INFANT FEEDING. 

With a little practice, milk diluted ten times with water 
can be curded with rennet so that all of the curd will 
unite into one small piece. Without the addition of the 
dilute acid the curding process takes more time. If the 
casein is first precipitated by the acid the rennet will not 
cause it to clot. Occasionally specimens of milk will be 
met that do not readily form a curd with rennet. Pas- 
teurized and sterilized milk do not readily curd with rennet. 

38. Mixed Milks and Whey . — M arke t m ilk is a mixture 
of the secretion of many cows, and varies between three 
and five per cent of fat; but the milk of any particular 
milkman is quite uniform from day to day. It is useless 
then to think of average milk, so a number of complete 
analyses of milks within the normal range will be given. 
In many of the older analyses of milk the total proteids 
are called casein ; in other analyses the total proteids and 
the casein have been determined, and the difference be- 
tween these has been called albumin. In some more re- 
cent analyses the proteids other than casein have been 
determined, but there is as yet no generally accepted 
method of separating these proteids. 

As the relation between the quantity of casein and so- 
called albumin of milk has been made the basis of a system 
of infant feeding, some space will be given to this subject. 

It has been pretty generally believed and accepted, on 
the authority of Koenig and Blyth, that there is a quite 
constant ratio between casein and albumin of cow's milk, 
there being about five times as much casein as albumin. 
Van Slyke, in looking over a large number of analyses of 
normal milks reported by different analysts, found that 
the ratio between casein and albumin in these analyses 



COW'S MILK 



7i 



was as high as ten parts of casein to one of albumin, and 
as low as three parts of casein to one of albumin. He 
then began a systematic examination of milk to deter- 
mine the ratio between casein and albumin, if there was 
one. This test, which is remarkable, extended over a pe- 
riod of several years ; and during the first year the milk of 
fifteen hundred cows in four counties of New York State 
was used at several cheese factories. The total quantity 
of milk used was 214,684 pounds, and 106 analyses were 
made in triplicate to exclude any chance of error. His 
conclusions then were: "Our results show that the rela- 
tion of albumin to casein is a very variable one instead of 
constant, and in no single instance did any sample of the 
mixed normal milk contain as much as five parts of casein 
for one of albumin, the highest being 4.9, while the aver- 
age was 3.76 parts casein for one of albumin." 

In the following analyses of Van Slyke, the casein and 
albumin (total proteids), and casein were determined direct- 
ly, and the water, albumin, sugar, and ash indirectly. These 
analyses were made in triplicate both for the milk and the 
whey, and are exceedingly useful in showing the range of 
composition of mixed milks that may be met anywhere, and 
the composition of whey made from a particular milk. 





v.' c 


•3 I/i C 


. c 


•0 . . 
g.S'3 

|ll 




Difference. 

Albumin, 

albumoses, 

and 
peptones. 


Milk 

Whey 

Milk 

Whey 

Milk 

Whey 


88.40 

93-13 
87.81 
92.60 

87.97 
92.83 


II.6O 

6.87 

12.19 

7.40 

I2.03 

7-17 


3-OS 
.28 

3.10 
•33 

3-30 
•36 


2.64 
.69 

2.72 
.71 

2.63 
• 7 1 


I 98 
2.06 
2.03 


O.66 
.66 
.60 



6.37 

6.36 



74 



INFANT FEEDING. 



*5 o 



Casein and 
albumin. 
Per cent. 


1 asein. 
Per cent. 

Difference. 
Albumin, 


hi 

3 <« a 

~ p. 


2.65 
•"2 


I.97 


.68 


3.20 

.88 


2-43 


77 


3M 
.81 


2.47 


67 


3-09 
.81 


2.51 


• 53 


3-15 

•33 


2-44 


71 


3-15 
.86 


2-47 


.68 


3-13 

•35 


2.49 


.64 


3.06 

•83 


2.48 


.58 


3.08 
.82 


2.46 


62 


3.18 

.86 


2-53 


65 


3-t8 

.83 


2.56 


.62 


3-22 

.88 


2.49 


73 


3-29 

.87 


2.68 


61 


3-45 

.87 


2.77 


68 


3-36 
.89 


2.68 


68 


3-48 
.91 


2.76 


72 


3-33 
.89 


2.62 


76 


3.48 
•94 


2-75 


73 


3-44 
.90 


2.64 


80 


3-59 
•94 


2.90 


69 


3.46 
.88 


2.71 

.... | .. 


75 



Milk . . 
Whey. 

Milk . , 
Whey. 

Milk . , 
Whey. 

Milk , 
Whey. 

Milk- 
Whey. 

Milk 
Whey. 

Milk . 
Whey. 

Milk. 
Whey. 

Milk 
Whey. 

Milk 
Whey. 

Milk 
Whey. 

Milk 
Whey. 

Milk , 
Whey. 

Milk . 
Whey. 

Milk . 
Whey. 

Milk . 
Whey , 

Milk . 
Whey. 

Milk . 
Whey. 

Milk . 
Whey. 

Milk . 
Whey., 

Milk . 
Whey. 



87.94 
92. S2 

S7-52 
9 2 -93 
S7.52 
93.02 

S7.80 
93-27 

87-45 
93-Q4 

37-33 
93-05 
87.46 
93-17 

87.41 
93.18 

37.54 
93-19 

37-34 
93.16 

87.41 

93-23 
87.29 
93.10 

87.00 
93.04 
86.91 
93-17 
86.92 
93.18 

86.59 
93-04 

86.16 
92.50 

86.53 
93.28 

86.61 
92.91 

86.31 
93.00 

S6.54 
92.96 



12.06 

7.18 

12.4S 
7.07 

12.48 

6.98 

12.20 

6-73 

12.55 
6.96 

12.62 
6-95 

12.54 

6.83 

12.59 

6.82 

12.46 
6.81 

12.66 
6.84 

12.59 
6.77 

12.71 
6.90 

13.00 

6.96 

13.09 

6.83 

13.08 
6.82 

13.41 
6.96 

13.84 
7- 50 

13-47 
6.72 

13-39 
7.09 

13.69 
7.09 

I3-46 
7.04 



3-35 
•34 

3-45 
•23 

3-50 
.38 

3-55 
• 40 

3.60 

.32 

3-65 
.30 

3-70 
•32 

3-75 
■34 

3. So 
•44 

3-35 
•37 

3.90 
•36 

3-95 
•34 

4.00 
•30 

4-05 

•37 

4.10 

•35 

4- '5 
•35 

4.20 
•34 

4-25 
.32 

4-30 
.31 

4-35 

.35 

4.40 
.40 



6.06 
6. 12 

5.83 
5-90 

5-3 4 
5-79 

5-56 
5-52 

5- 80 

5.81 

5-32 
5-79 

5-71 
5-66 

5.73 
5.65 

5-53 
5-55 

5-03 
5-61 

5-51 
5.58 

5-54 
5-68 

5-71 
5-79 



5-59 
5-59 
5.62 

5.58 

5-73 
5- 7o 

6.26 
6.27 

5-74 
5.46 

5.65 
5.88 

5-75 
5-71 
5.60 
5.76 



COW'S MILK. 



75 



Milk 
Whey 

Milk 
Whey 

Milk 
Whey 

Milk 
Whey, 

Milk 
Whey. 













6 - 


w 














t- c 




. a 












*J v 








rt " 

n 






3^ 




Diffei 
Albu 

album 

an 

peptc 


85.90 


I4.IO 


4-55 


3.62 


3.06 


.56 


92.94 


7.06 


•34 


• 97 








85.18 


14.82 


4.85 


3-93 


3-13 




80 


92.50 


7.50 


•3 1 


I.-OI 








85.37 


14.63 


5.00 


3-99 


3.14 




85 


92.62 


7-38 


•30 


1.03 








85.13 


I4.87 


5-IO 


4.00 


3.18 




82 


92.56 


7-44 


•34 


1.04 








S5.06 


14.94 


5-25 


3-86 


3.10 




76 


92.74 


7.26 


.36 


1.04 









3-d u 
W a <u 



5-93 
5-75 
6.04 
6.18 

5.64 
6.04 

5-77 
6.06 

5.83 
5-86 



In a series of analyses made in another year, the pro- 
teids were further separated and the range for the year 
was: Total solids, 12.29 to 13.39 per cent; fat, 340 to 
4.10 per cent; casein, 2.19 to 2.26 per cent; albumin, 
0.28 to 0.38 per cent; albumoses, 0.30 to 0.50 per cent. 

Babcock and Russell in 1897 published the following 
analyses of the proteids of many samples of cow's 
milk: 



_ B £ 


a s'c 


ilss 1 






c a 


c 


= S S 


S Mjj 


% 0" 


£ D. M « 






'in " 


|"gss 


Ej u 




6 -U 


•Q a " S 




&- 2 S 
aft 


3| 


5"8iS 




O.46 


0.34 


O.08 


2.87 


2. 12 


0.50 


0.25 




51 


•43 


.04 




3.18 


2.68 


.25 


.25 




52 


.40 


.04 




3-25 


2.50 


•31 


• 50 




53 


•39 


• 05 




3-3i 


2.44 


.31 


.56 




55 


.46 


.04 


X6.25 = 

> (by « 


3-43 


2.87 


•25 


.31 




ss 


.46 


• OS 


3.43 


2.87 


.31 


.25 




56 


• 45 


.04 


author) 


3-50 


2.81 


•25 


.44 




57 


•43 


.05 




3.56 


2.68 


•31 


.57 




58 


•47 


.07 




3.62 


2.94 


•43 


• 25 




58 


• 4i 


.08 




3-62 


2.56 


.50 


.55 




59 


• 44 


.04 




3.68 


2-75 


.25 


.68 




60 


.46 


.04 




3-75 


2.87 


.25 


.63 


.72 


• 56 


.70 J 




I 4.50 


3-50 


•44 


•56 



The following analyses made by a professional chemist 
of high grade Jersey milk (Briarcliff Farms) will show the 
relative proportions of fat and proteids in very rich milk: 



76 



INFANT FEEDING. 



April, 1900 

May, 1900 

June, 1900 

July, 1900 

August, 1900. . . . 
September, 1900 . 
October, 1900 . . . 
November, 1900 . 
December, 1900.. 
January, 1901 . . . 
February, 1901 . . 
March, 1901 

April, igoi 

May, 1901 

June, 1901 

July, 1901 

August, 1 90 1 . . . . 
September, 1901 . 
October. 1901 . . , 
November, 1901 . 
December, 1901 . 
January. 1902 . . . 
February, 1902 . . 

March, 1902 

April, I902 

May, 1902 

June, 1902 

July, 1902 

August, 1902. . . , 
September, 1902, 
October, 1902 . . . 
November, 1902 . 
December, 1902. 
January, 1903 . . . 
February, 1903 . , 
March. 1903 

April, 1903 

May, 1903 

June, 1903 

July, 1903 

August, 1903. . . . 
September, 1 903 . 
October, 1903 . . . 
November, 1903 . 
December, 1903 . 
January, 1904 . . . 
February, 1904 . . 



83 
72 
55 
20 

34 
3i 
5 38 
5 20 
5.69 
5.72 
5-57 











.- 1 


%& 


<->X 


72^5^. 


C Z 




0. 


s v_<D 


•3.48 


4-88 


3.5S 


4.84 


3-59 


4-85 


3-54 


4.84 


3-58 


4-79 


3-75 


4.84 


3-73 


4-75 


3S2 


4.86 


3-77 


4-79 


3- "6 


4-83 


3-67 


4.87 


3-57 


4.90 


3.66 


4.89 


3-54 


4.S4 


3-59 


4.91 


3- 50 


4.71 


3-54 


4.78 


3-56 


4-77 


3-87 


4.89 


3-87 


4.86 


3-85 


4.81 


3.82 


4.89 


3- 72 


4.88 


3-57 


4.S4 


3-53 


4.84 


3-67 


4.92 


3-59 


4-77 


3-48 


4.84 


3-66 


4-75 


3-65 


4.81 


3.78 


4.83 


3-78 


4-83 


3-95 


4.82 


3.81 


4.88 


3-8i 


4.82 


3-76 


4.86 


3-56 


4-85 


3-65 


4.91 


3-56 


4.87 


3-45 


4.64 


3-47 


4.92 


3-48 


4.81 


3-55 


4-74 


3-75 


4.80 


3-84 


4.S6 


3.81 


4.71 


3-75 


4.87 



^•75 
•73 
•72 
•75 
•74 
•75 

• 75 
•75 
•76 
•74 
•75 
•73 
•75 
•75 
.76 
•73 
•74 
•74 
•74 
.76 
•77 
.76 
■ 75 
•74 
•73 
•73 
•74 
•72 
•75 
.72 
.76 
•74 
•77 
.76 
•75 
•73 
•73 
■73 
•74 
•75 
.72 
•73 

• 75 
•74 

• 75 
.76 
.76 



39. Cream. — The fat globules of milk being much 



COW'S MILK. 77 

lighter than the other ingredients of the milk have a ten- 
dency to rise to the surface if the milk is allowed to re- 
main undisturbed for any length of time. The separa- 
tion of the fat from the other ingredients of the milk is 
not complete, so cream is a mixture of milk elements in 
which fat greatly predominates. 

40. Cream Separating. — There are three methods of 
separating cream from milk. (1st) The shallow-pan sys- 
tem in which the milk is poured into wide, shallow pans; 
(2d) the deep-setting system, in which the milk is put into 
tall, narrow vessels, and allowed to stand; and (3d) the 
centrifugal process in which the milk is run through a 
bowl which revolves at a high rate of speed. 

41. Gravity Cream. — Cream that is allowed to rise 
naturally and is then skimmed by hand is called gravity 
cream. The separation of cream in the shallow-pan sys- 
tem is not very complete, and this system is not used 
much in producing cream for market. 

Strange to say, if milk is put into tall narrow vessels 
and placed in cold water at 45 F., the cream rises quickly 
and completely, the skim milk often containing not over 
0.2 to 0.4 per cent of fat. This system is well illustrated 
by bottled milk, on which the layer of cream can usually 
be plainly seen. 

42. Time Required for Cream to Rise. — If milk is 
placed in cans or bottles immediately after milking, before 
it has had time to cool, the separation of cream is rapid. 
At the end of four hours nearly all the cream that will rise 
will have risen ; but if the milk has been stirred and cooled 
before it is set for the cream to rise, the separation will take 
many hours longer and will not then be as complete (132). 



78 



INFANT FEEDING. 



Other conditions affecting the separation of cream are 
the size of the fat globules, the passing of milk through 
a centrifugal machine as is sometimes done to remove 




Fig. 16.— Microscopic Appearance of Normal Milk. (Babcock and Russell.) . Fat globules ir 
clusters. 



Wit. - -> o >■ ■» ,.**« '** -4 *> « , ^>^- - '» JO 



o^ 



OS-, S O- . 6 -. 




Fig. 17.— Microscopic Appearance of Centrifuged, or Heated Milk. (Babcock and Russell.) Fat 
globules not in clusters. 

dirt, and heating the milk. The smaller the fat globules 
the longer time is required for the cream to rise. In the 
milk of certain breeds of cows the fat globules are very 
small; such milk does not cream well. In rich milks, 



COW'S MILK. 79 

containing over four and one-half per cent of fat, the fat 
globules are larger and creaming is rapid and complete 
(36): Passing milk through a centrifugal machine breaks 
up the natural arrangement of the fat globules ; and gravity 
cream from such milk separates slowly and incompletely, 
is very thin and limpid, and apt to deceive in richness one 
who has not tested it. Such cream, containing over 
twenty per cent of fat, is often apparently not thicker than 
rich milk. Heating milk also prevents its creaming well. 
43. Centrifugal Cream. — The first centrifugal cream 
separators were simple buckets of milk which were whirled 
until the cream rose, when it was skimmed by hand. Later 
a circular bowl was devised, which when revolved three 
thousand to five thousand times a minute caused a rapid 
separation of cream. The milk arranges itself into several 
layers. The dirt and heavy particles, such as epithelium 
and manure, are thrown against the side of the bowl; next 
comes the skim milk, and then the cream which is lightest 
is nearest the centre of the bowl. A clear idea of the 
state of the milk in a separator bowl can be had by imagin- 
ing a quart bottle of milk on which the cream has risen 
being laid on its side without the arrangement of the 
cream being disturbed. The bottom of the bottle with 
its sediment would correspond to the side of the bowl 
and the mouth of the bottle to the centre of the bowl. 
Now imagine a small stream flowing from the layer of 
cream near the mouth of the bottle and another from the 
skim milk near the bottom of the bottle, with the bottle 
kept filled all the time by a fresh supply stream of milk 
that separated as soon as it entered the bottle into the 
layers of dirt, skim milk, and cream, and the centrifugal 
cream separator will be understood. 



8o 



INFANT FEEDING. 



The illustration shows a simple style of separator bowl 
in operation. 

The length of time the milk remains in the bowl of 
the separator can be regulated and the cream made richer 

U 




Fig. 18. — Centrifugal Cream Separator. (Wing.) a, Inflowing milk ; 
by outflowing skimmed milk ; c. outflowing cream. 

or poorer in fat accordingly. The shorter the time the 
milk is in the bowl the poorer the cream is in fat. 

44. Separator Slime. — After a quantity of milk has 
been passed through a separator there is found sticking to 
the inside of the bowl what is known as separator slime. 
Its composition is variable, but it generally consists of 
epithelium, mucus, pus, blood, dirt, manure, hair; and if 
the milk is slightly sour, of quantities of precipitated 
casein. There is always more or less of this separator 
slime, even if the best and cleanest milk is used. It is 
not necessarily filth, although when obtained from dirty 
milk it contains much filth. 



COW'S MILK. 81 

45. Difference between Gravity and Centrifugal Cream. 
—When milk leaves the cow the fat globules are free ; but 
shortly after milking they form themselves into little 
groups, supposedly under the action of a substance similar 
to fibrin. When milk is passed through a separator or is 
heated for that matter, this arrangement of the fat globules 
is broken up (43). There is also a separation of the pro- 
teids. To quote Babcock and Russell: "A chemical 
analysis of fresh separator creams showed that from eigh- 
teen to thirty-eight per cent of the total protein was present 
in the form of albumoses and peptones," while they found, 
on an average, that in fresh whole milk 9.69 per cent of 
the protein was albumoses and peptones. Hence there 
is a great difference, both physical and chemical, between 
gravity and centrifugal creams ; and, in the author's opin- 
ion, gravity cream from bottled milk is to be preferred for 
use in infant feeding on the principle that the less the 
milk is manipulated and the ingredients are separated, 
the better. 

In butter-making this separation of proteids and change 
in form of the emulsion of the fats in centrifugal cream is 
not a disadvantage, for butter can be made from centrifugal 
cream without the "ripening" or partial souring that 
gravity cream must undergo before butter can be made 
from it. For many commercial purposes, however, cen- 
trifugal or heated (Pasteurized) creams cannot be used. 
Charlotte russe and ice-cream makers and cooks insist on 
having gravity creams because they will " whip," while 
centrifugal or Pasteurized creams will not " whip." 

Cream Thickeners. — To overcome the objections thus 

inherent in centrifugal cream, Babcock and Russell in- 
6 



82 INFANT FEEDING. 

vented a process of giving "body" to creams, which con- 
sists of adding a syrup of lime, which they call " viscogen," 
to the centrifugal or Pasteurized creams. Syrup of lime 
can be had at any drug store and contains six and one- 
half per cent of lime. A few drops of this syrup of lime 
will cause cream or milk to become thick and viscid, its 
action being on the mucoid proteid (35) of the milk — the 
distinctive property of mucin being that of forming mu- 
cilaginous, stringy solutions when acted upon by a trace 
of alkali. Any one having much to do with milk or cream 
should try adding syrup of lime to both and should also 
taste them when thickened. The taste is distinctive but 
not unpleasant. 

Another method of thickening cream consists of add- 
ing solutions of gelatin. Such thickeners are sold by 
dairy supply houses under different names (see cream, al- 
buminoid) (63). 

46. Condensed Milk. — There are two distinct kinds of 
condensed milk which are widely used — fresh condensed 
milk and canned condensed milk. Milk is first heated 
up to near boiling point and a large portion of water then 
removed by boiling at a low temperature in vacuum pans. 
The condensed milk is then filled into bottles or cans if 
it is to be sold in its fresh state ; or cane sugar is added, 
and it is then filled into tin cans and hermetically sealed 
if it is to be kept for any length of time. 

During the past three or four years there has been a 
greatly increased sale of unsweetened condensed milk put 
up in sealed tin cans. These milks are limpid, yellow in 
color, and have a strong " cooked " taste. They are sold 
under the name of " Evaporated Creams," a misleading 



COW'S MILK. 83 

term, as many brands of condensed milk contain more 
fat than these so-called creams. The labels on the cans 
of evaporated cream usually state that it is simply pure 
milk thoroughly sterilized and reduced to the consistency 
of cream. These evaporated creams are apt to become 
putrid when diluted and exposed to the air, and for this 
reason are being put up in small cans, the contents of 
which will be used up quickly. 

There has recently been devised a process of condens- 
ing milk without the aid of heat. The cream is first re- 
moved by a separator (43) and the skim milk is then 
frozen. As fast as crystals of ice appear the milk is 
stirred and in time becomes like slushy snow. The wa- 
ter in crystallizing throws out the proteids, sugars, and 
mineral matter of the milk as a syrupy mass. The frozen 
milk is then put in a centrifugal machine, such as is used 
in driving out the molasses from raw sugar, and the syr- 
upy mass of proteids, sugar, and mineral matter is thus 
separated from the ice crystals. The cream is now mixed 
with the syrupy mass and the mixture, when diluted? with 
three parts of water, equals the original milk. 

As yet this condensed milk is not on the market, but 
if it becomes possible to render it sterile without the use 
of heat, so that it can be kept indefinitely, it is likely to 
become a very useful article of food. 

The following analyses of condensed milks furnished 
the author by Major Alvord, Chief of Dairy Division, 
United States Department of Agriculture, are of milks 
bought in San Francisco. Only four States, Illinois, 
New York, Ohio, and Oregon, have laws (79) relating to 
the quality of condensed milk, so any kind of condensed 



8 4 



INFANT FEEDING. 



milk can be sold in the other States. These analyses do 
not represent all the brands in the market by any means, 
but they do show the range in quality likely to be met 
with. Any of the evaporated creams or unsweetened 
condensed milks may be tested in a few moments by the 
fat and specific gravity test (75) when diluted with two 
parts of water, quite accurate results being obtained. 
Sweetened condensed milks cannot be easily tested in 
this way, as the excess of sugar interferes with the fat 
test. 



Unsweetened Condensed Milk. 
Whole Milk (so-called Evaporated Creams). 



Water. 


Fat. 


Proteids. 


Milk 
sugar. 


Solids 


Cane 
sugar. 


Ash. 


Brand. 


68.27 


IO.IO 


7-36 


II.03 






I.85 


Ideal. 


69.17 


IO.4O 


S.OI 




20.43 




1.79 


California Poppy. 


69.58 


9.02 


7-77 


IO.62 






I.80 


Highland. 


72.78 


9-37 


7.66 




17.85 




1. 6l 


Lily. 


72.92 


8-34 


6.00 




IS.74 




I. 71 


Red carnation. 



Evidently Skimmed or Partly Skimmed Milk. 



74-29 


1.80 


8.97 




23.91 




2-39 


80.58 


5.70 


7.02 




13-72 




1.69 



Monarch. 
"99." 



Sweetened Condensed Milk. 
Whole Milk. 



Water. 


Fat. 


Proteids. 


Milk 
sugar. 


Cane 
sugar. 


Ash. 


Brand. 


23.70 


IO.82 


8-54 


14.17 


39-85 


2.13 


Milk Maid. 


25-25 


IO.62 


7.90 


12.53 


40.56 


I.84 


Nestle's. 


26.O3 


8-54 


7.I7 


12.45 


41.82 


I.S7 


Gold Lines. 


27.52 


8.81 


7.48 


12.77 


41.06 


I.63 


Eagle Falcon. 


23.41 


S-44 


7-23 


II.69 


41.52 


I.80 


Eagle. 



COW'S MILK. 



S5 



Sweetened Condensed Milk — {Continued). 
Evidently Skimmed or Partly Skimmed Milk. 



Water. 


Fat. 


Proteids. 


Milk 
Sugar. 


Cane 

Sugar. 


Ash. 


Brand. 


25.68 

25.88 
28.48 
29.67 


O.71 
O.96 
O.60 

2.47 


I0.35 

IO.64 

7.9O 

I0.45 


16.85 
27.38 
18.76 
19.05 


43-09 
34.07 
41.77 
36.OO 


2.48 
2.56 
2.04 
2.29 


Cowslip. 
Snake. 
Farm. 
Pearl. 



Condensed Creams. 



Water. 


Fat. 


Proteids. 


Solids not fat. 


Ash. 


Brand. 


59.60 
65.26 
69.84 


34-19 
28.26 
23.83 




6.21 
6.48 
6.33 


0.53 
O.56 
O.67 


Dahl's Gold Medal. 

Empress. 

California. 



CHAPTER XL 

BACTERIOLOGY OF MILK. 

47. Practically all of the changes that take place in 
milk that is kept for any length of time are the result of 
bacterial growth. The mere presence of bacteria in milk, 
even in large numbers, however, does not necessarily 
mean that the milk is harmful and unfit for use as food. 
A great deal of misapprehension exists on this point, and 
it can be removed only by a better knowledge of the func- 
tion and properties of bacteria. To many, bacteria sug- 
gest disease, and it has been thought that all bacteria 
should be destroyed ; but now it is known that their in- 
discriminate destruction would prove to be a great calam- 
ity, as bacteria are absolutely essential to the life of plants 
and animals, the function of most bacteria being to reduce 
to gases, and soil, which is a mixture of earth and decom- 
posing organic matter, all lifeless organic matter, which 
then serves as food for plants, and these in their turn 
nourish all animal life. Bacteria serve other useful and 
valuable purposes. The delicate flavor of June butter is 
caused by bacterial action, and the manufacture of cheese 
is largely, if not wholly, dependent on the growth of bac- 
teria in milk. It is true that disease is caused by some 
kinds of bacteria, but all bacteria should not be con- 
demned and destroyed, even if this could be done, be- 
cause a few species cause disease. 



BACTERIOLOGY OF MILK. 87 

As bacteria are everywhere present and are sure to be 

found in milk, a knowledge of their nature and of the 

conditions under which they gain ac- 

C~V r~^) s-O cess to the milk and cause it to change 

or become harmful is essential. 




\^J s*\ ^yL 48. Bacteria. — Bacteria are micro- 

(~y^^ \^J scopic, unicellular, colorless plants, be- 
longing to the class called fungi. They 

Fig. 19.— Showing Budding 

of Yeast. (Conn.) are closely related to ^ 

the yeasts, but are (J (J ^. 

smaller and also differ from the yeasts in f~\ r^\ f< 
their methods of reproduction. Yeasts ' O 

multiply by budding, while bacteria mul- FlG ^.-showing Fis- 

rJ J ^ »> sionof Bacteria. (Conn.) 

tiply by two different methods : 1st. By 
fission, in which the cell divides through the centre, pro- 
ducing another full-fledged bacterium. 2d. By sporula- 
tion, in which spores are formed in the interior of the cell,, 
which breaks up and sets them free. These spores when 

placed in favorable 
surroundings germi- 
nate and become ac- 
tive bacteria. 

Not all species of 
bacteria are spore- 
bearing, and this fact 
has great importance 

Fig. 21. — Showing Formation of Spores. (Conn.) ° x 

in the preservation of 
milk and food ; for while active bacteria are almost with- 
out exception easily destroyed by a moderate degree of 
heat, spores in water or milk are not destroyed by boiling. 
They may be dried and kept for months or years, and then 




88 INFANT FEEDING. 

when placed under favorable conditions will germinate 
and develop into active bacteria. Many of the harmful 
changes in milk are caused by spore-bearing bacteria. 




Fig. 22.— a, Spheres; i, rods; c, spirals. (Conn.) 

Classification of Bacteria. — Bacteria are divided ac- 
cording to their form into three groups: 
i. Spherical bacteria — coccus. 

2. Rod-shaped bacteria— bacillus and bacterium. 

3. Spiral bacteria — spirillum. 




Fig. ay— a, Streptococcus ; b, micrococci 



sarcina. (Conn.) 



Spherical bacteria are further classified according to 
the way in which they group themselves during the proc- 



BACTERIOLOGY OF MILK. 89 

ess of division, as streptococcus, in chains; micrococcus, 
in irregular masses, and sarcina, solid masses in groups 
of four. 

49. Bacteria that grow best in the presence of oxygen 
or air are called aerobes; those that grow best in the absence 
of oxygen or air are called anaerobes. Bacteria which 
will grow only under one of these conditions are called 
obligate aerobes or anaerobes, while those species that will 
grow either in the presence or absence of oxygen are 
called facultative aerobes or anaerobes. The greater 
number of species of bacteria attack and live upon lifeless 
organic matter and are called saprophytes ; those species 
that attack living matter are called parasites. 

50. Rate of Growth of Bacteria. — Bacteria increase in 
numbers at a prodigious rate. If nothing interfered, in 
twenty-four hours a single bacterium would produce about 
seventeen million others. This rate of increase is not 
met with in practice ; but, according to Conn, a specimen 
of milk containing 153,000 bacteria to the cubic inch con- 
tained twenty-four hours later 85,000,000, and a sample of 
fresh cream, containing 44,000 bacteria to the cubic centi- 
metre, contained 1,300,000,000 when sour enough to churn. 
The rapidity of increase depends largely on the tempera- 
ture. Below 45 F. there is comparatively little growth 
of bacteria; but as the temperature approaches ioo° F., 
the rate of growth increases rapidly. 

51 • Food of Bacteria. — Most bacteria must have a food 
supply of nitrogenous matter (proteid), carbohydrates 
(sugar, starch, or cellulose), mineral matter, and water. 
Furthermore, their food must be in a soluble form so that 
it can pass through the cell wall of the bacteria and be 



90 INFANT FEEDING. 

not too concentrated. Bacteria cannot grow in substances 
as thick as syrup. Bacteria that can attack insoluble 
matter secrete enzymes that digest or convert the insolu- 
ble food material into assimilable forms. Thus in milk 
some species of bacteria will secrete rennet that will curdle 
the casein of milk, and trypsin that will dissolve or pep- 
tonize it. Other bacteria also secrete enzymes that will 
digest or decompose starch, sugar, cellulose, fat, urea, and 
other substances. 

52. Souring of Milk. — As every one knows, the most 
common change in milk is souring. Milk sours because 
several species of bacteria attack the sugar of the milk 
and convert it into lactic acid, which throws the casein out 
of solution (37). These bacteria may be classed as harm- 
less bacteria, for sour milk is a wholesome article of food 
and is used in cooking. Before baking powder became 
so common, sour milk was used with baking soda to make 
cake and biscuit rise. 

It is popularly believed that thunder causes milk to 
sour, but it has been found that the thunder or electricity 
of the air has nothing to do with the souring of the milk, 
but that the atmospheric conditions during a thunder 
storm are favorable to the growth of lactic-acid bac- 
teria. 

Fresh milk always contains several species of bacteria, 
and if the milk is warm enough they commence to grow 
at once. The conditions in the milk are generally most 
favorable for the growth of the species that attack the 
sugar and produce lactic acid; and if there are any of 
these bacteria present, as is generally but not always the 
case, they soon outstrip the other species and kill them 



BACTERIOLOGY OF MILK. 91 

off; hence after a few hours an examination of the milk 
will often show ninety-nine per cent of the bacteria in the 
milk to be of the souring variety. When bacteria that 
cause souring are not present, the other species which 
attack the fat and proteids of the milk grow and produce 
rancidity of fat and many changes in the proteids. 

53. Peptonizing Bacteria in Milk. — When the proteids 
of milk are attacked by bacteria, they may be first curdled 
by rennet and then peptonized by trypsin, both secreted 
by bacteria, or the proteids may be peptonized without 
first being curdled. Such milk does not sour, but acquires 
a bitter taste. Bacteria that produce these changes are 
normally present in milk, but are usually held in check 
by the souring species; sometimes, however, poisonous 
products are produced by bacterial action on proteids of 
milk. 

54' Decomposition of Proteids. — The decomposition of 
proteid matter is brought about chiefly by the action of 
decomposition bacteria. When the process of decomposi- 
tion is caused by aerobic bacteria in the presence of an 
abundance of air, it is called decay and the proteid matter 
is reduced to simple harmless forms ; but, when the de- 
composition is caused by facultative aerobic or anaerobic 
bacteria in the absence of an abundance of air, the process 
is called putrefaction. Here the proteid matter is not 
completely reduced to simple harmless forms ; foul-smell- 
ing gases are evolved and oftentimes substances that are 
intensely poisonous are also produced. These poisons 
may be secretions or excretions of the putrefactive bac- 
teria, or partially reduced proteid matter. Under the ac- 
tion of aerobic bacteria, in the presence of plenty of air, 



9 2 



INFANT FEEDING, 



these gases and poisons are destroyed. The process in- 
volved in the decay or putrefaction of proteid matter is 
not understood. Putrefactive bacteria are present every- 
where, but particularly in rich soil and in 
manure. A gram of rich soil may contain 
100,000,000, and a gram of fresh cow's 
manure as many as 375,000,000 bacteria, 
most of which will cause decomposition 
in proteid matter. This fact suggests the 
importance of keeping cows and stables 
clean. 

Other Bacterial Changes in Milk. — 
Slimy milk is caused by bacteria found in 
water, and " gassy " milk by bacteria found 
particularly in manure particles. Soapy, 
blue, red, and yellow milks are also the 
result of bacterial action, but are not 
common (see Fig. 85). 

The bacterial changes of milk may be 
summed up as 
souring, pep- 
tonizing, pu- 
trefactive, and 

the development of odors, bit- 
ter taste, sliminess, soapiness, 
colors, and gases. 

Bacterial Diseases Trans- 
mitted by Milk. — Typhoid 
fever is easily transmitted by 
infected milk. Outbreaks of diphtheria and scarlet fever 
have been traced to milk supplies, and tuberculosis may 




Fig. 24. -Slimy Milk. 
(Russell.) 



Fig. 25. -Udder and Teat. (Russell.) 



BACTERIOLOGY OF MILK. 



93 



possibly but not necessarily be caused by milk containing 
tubercle bacilli (see Chapter XV.). 



y. 









How Bacteria Get into Milk and Increase in 

Numbers. 

55- From the Cow's Udder. — Just inside the cow's teat 
is a small cavity that always contains a small quantity of 
milk. During the intervals between milkings bacteria from 
the air lodge on the moist teat and make their way into 
this cavity where they grow. To quote Russell : " As a rule 
the number of different species found in the fore milk is 
usually small, not mOre than one or two forms being pres- 
ent at any time. As 
to the character of 
these forms data are 
conflicting. Har- 
rison reports finding 
peptonizing bacteria 
in some, and Mar- 
shall states that or- 
ganisms are found 
that resist pasteuriz- 
ing. . . . Bolley in 
thirty experiments 
found twelve out of sixteen species to belong to the 
lactic-acid class. ... If the fore milk is received into a 
separate vessel and kept protected from the air, it will be 
generally noted that it sours more rapidly than the re- 
mainder of the milk." In the report of a series of 
bacterial examinations of milk, D. H. Bergy (Penn. Dept. 
Agr. Rept., 1900) states: "Milk taken directly from the 




■Bacteria from Cream. (Conn.) 
good butter. 



and d produce 



94 INFANT FEEDING. 

udder in the ordinary way and collected in sterile test 
tubes was always found to contain bacteria of the group 
streptococci. The number in the first milk drawn was 
usually greater than [in] the latter portion." Strepto- 
cocci are usually looked upon by physicians as dangerous 
bacteria, but it has been found that good butter flavor is 
produced by some species of streptococci (Fig. 26). 



m 








mm- ^^% 


*^S0^^ 




m^Br ' 4K 


^-| : 


'-?" '\; 




fifl 


Si W, I 






'MS 


IE**"--- 








i— 










[ /2 — 




sfc&v' 






— . 




M^£§4 > -" 






t/M :. .. 











Fig. :*7- — Tuberculous Udder. (Russell.) 

If the first few jets from each teat are thrown away, the 
remaining portion of the milking will be quite free from 
bacteria, provided the cow has no disease of the udder. 
No milk from a diseased udder should be used as food. 
Tuberculous udders always secrete milk containing tu- 
bercle bacilli, and although no one knows how frequently 
bovine tuberculosis infects human beings through milk, 
no risk should be taken. When a cow's udder is tuber- 



BACTERIOLOGY OF MILK. 95 

culous, it is time to stop the use of her milk, whatever 
may be said of the safety of the milk from cows that 
simply react to the tuberculin test.* 

56. From the Cow's Body. — If the cow's body is not 
kept clean, more or less dirt is bound to be loosened and 
to fall into the milk pail, along with some hairs, during the 
process of milking. On a single cow's hair several hun- 
dred bacteria have been counted, and, as previously stated, 
soil and cow's manure, which is the dirt usually found on 
the cow's body, contains millions of bacteria per gram (54). 
If the cow has been wading in slimy, stagnant water, the 
scum from this water dries on the cow's body and some 
of it will get into the milk ; this dried scum is particularly 
injurious to milk. The bacteria that get into milk with 
filth are, as a class, the ones that cause the most damage 
to milk as a food, for many of these species decompose or 
putrefy the proteids of the milk. They can be kept out 
of the milk by keeping the cows clean. 

Example t : Milk from four dirty cows in a clean barn 
with clean milkers gave an average of ninety thousand 
bacteria to the cubic centimetre. Milk from four other 
cows of the same herd, carefully cleaned and milked by 
the same man, gave an average of only two thousand. 

57- From Dust. — Stable dust contains enormous 
numbers of bacteria, and if the cows are eating dry 
hay, or if the milker's clothes are dusty, the milk will 

*This test consists of injecting into an animal certain products de- 
rived from tubercle bacilli. If the animal is tuberculous they cause a rise 
of temperature. 

\ Report of the summer work of the Milk Commission of the Medical 
Society of the County of New York. (Bacterial examinations made by 
Dr. Sarah Belcher.) 



96 INFANT FEEDING. 

receive a great many bacteria with the dust that is sure 
to settle into the milk pail. Dust can be kept out of milk 
by wiping the cow with a damp cloth and by sprinkling 
the stable. 

Example*: Milk from each of twelve cows in a stable 
showed low bacterial count except from one which stood 
next to a pile of dry feed ; her milk contained one mil- 
lion bacteria to the cubic centimetre. 

58. From the Milker. — If the milker's hands are chap- 
ped or not clean, or if he is diseased, or is nursing a person 





Fig. 28. — A, a, Improper joints in dairy utensils. B, Proper joints closed with solder. 
(After Russell.) 

suffering from some infectious disease, the milk is more 
than likely to be infected by him. It is in this way that 
typhoid fever, scarlet fever, diphtheria, and infectious dis- 
ease germs find their way into milk. Milkers should wear 
white duck suits or blue overalls that are kept clean by 
frequent washing. 

59- From Dairy Utensils. — Any part of a milk pail, 
vat, cooler, can, bottle, or bottle filler that cannot be kept 
perfectly clean, always contains many bacteria that will 
infect any milk they may come in contact with, and for 

* See last note on page 95. 



BACTERIOLOGY OF MILK. 97 

this reason all dairy utensils should have perfectly tight 
smooth seams and joints; even then it is almost impos- 
sible to keep the best-made utensils free from bacteria. 
Washing utensils with ordinary well water or brook 
water may infect the milk with typhoid germs; they 
should be washed with boiling water and steamed if 
possible. 

Example*: With ordinary milk pail and strainer the 
bacterial count was eighty thousand; with sterilized pail 
and strainer the same day, in the same barn, and with 
the same cows five thousand bacteria to the cubic centi- 
metre were counted. 

60. By Growth. — When the milk leaves the cow it is at 
a temperature of nearly ioo° F., which is the ideal tempera- 
ture for rapid growth of bacteria. If the milk is allowed 



PROGENY OF A ,><r0 c 

SINGLE GERM 

IN TWELVE HOURS ^'ThT^LCoQ. 




m 



Fig. 29. — Showing the Effect of Cooling Milk on the Growth of Bacteria. (Russell.) 

to stand, the bacteria grow rapidly, and in a short time 
each bacterium will produce hundreds of others. This 
increase in numbers by growth may easily be prevented 
by: (1) promptly cooling the milk to below 45 F., and 
keeping it cool; (2) by heating the milk to destroy the 

* See last note on paj^e qs. 



9 8 



INFANT FEEDING. 



bacteria; or (3) by the addition of chemical preservatives. 
The following figures of Cnopf and Escherich, quoted by 
Russell, are highly instructive, as is also the illustration 
by Russell. 



Rate of Growth of Single Germ. 





Two hours. 


Three hours. 


Four hours. 


Five hours. 


Six hours. 


54°F 

97 c F 


4 

23 ' 


6 
60 


8 
215 


26 
1,830 


435 
3,800 





Bacterial Count of Milk. — From the foregoing it will 
be seen that bacteria originally get into milk principally 
through lack of cleanliness about the dairy, also that no 
matter how few bacteria were present in the milk originally, 
it will soon contain enormous numbers if allowed to stand 
for any length of time at anywhere near body tempera- 
ture. Therefore, counting the numbers of bacteria in 
natural milk — that is, milk that has not been heated to 
kill the bacteria or to which chemical preservatives have 
been added — is a valuable way of telling under what con- 
ditions it has been produced and kept. Milk produced in 
dirty surroundings will always contain large numbers of 
bacteria, while milk produced where cleanliness is the rule 
will contain few bacteria. If the milk is properly cooled 
and kept cool there will be but a slight increase in the 
numbers of the bacteria in the milk after milking. There- 
fore it is safe to say that natural milk containing few bac- 
teria came from a clean dairy and that the milk was kept 
cool ; and that natural milk containing large numbers of 
bacteria came from a dirty dairy, or was not kept cool if 
from a clean dairy, or that the dairy was dirty and the 
milk was also not cooled. Low bacterial count in natural 
milk means that the milk has been produced under clean 



BACTERIOLOGY OF MILK. 99 

conditions, and that little or no change has taken place 
in it. 

As all milk contains a certain number of bacteria, 
what is to be desired is a knowledge of what species of 
bacteria cause sickness and where they come from. Such 
information can be obtained only by much patient work 
on milk that has actually caused sickness. 

In the section on testing milk (p. 148) will be found a 
chapter by Prof. H. W. Conn, on the bacteriological ex- 
amination of milk. The great experience of Professor 
Conn and his many bacterial discoveries regarding milk 
make his methods of work of great value, and suggestive 
to workers not familiar with bacterial studies in milk. 



CHAPTER XII. 
PRESERVATION OF MILK. 

In the preceding chapter (60) it was shown that the 
bacterial development and changes in milk could be pre- 
vented (1) by heating to kill the bacteria; (2) by the addi- 
tion of certain chemicals; and (3) by keeping the milk at 
temperatures below 45 ° F., when bacteria do not grow to 
any extent. On these three principles all methods of 
milk preservation are based. 

61. Sterilization and Pasteurization. — Before the 
cause of the changes that take place in milk was discov- 
ered, it was known that scalding or boiling would prevent 
it from souring. With a knowledge of bacteria and their 
supposed always dangerous properties, came the belief 
that all milk for infants and possibly for adults should be 
sterilized — heated to 212 F., so as to kill all bacteria pres- 
ent. Such milk had a "cooked" taste, and its physical 
and chemical properties were changed (42), and few 
adults would use it. It was then discovered that at tem- 
peratures ranging from 140 to 175 F.,most of the bacte- 
ria found in milk were destroyed if the milk was properly 
handled during heating. This process is called pasteu- 
rization after Pasteur, who first used it to any extent. 
Russell states that in some milk pasteurized on a com- 
mercial scale at the Wisconsin Dairy School, there were 
less than one thousand bacteria per cubic centimetre in 



PRESERVATION OF MILK. 101 

half of the samples, while the average of twenty-five 
samples was 6,140 per cubic centimetre. Even at these 
low temperatures the taste of the milk is slightly changed 
and the natural arrangement of the fat emulsion is de- 
stroyed (42). 

62. In some cities milk dealers pasteurize their milk 
before delivering it to their customers, but such milk may 
in the end prove more injurious than natural milk. If 
the milk was originally dirty or contained as much as .2 
per cent acid produced by the growth of bacteria, it will 
not pasteurize satisfactorily, as many spore-bearing bacte- 
ria will be present. The heat destroys the active bacteria, 
most of which produce souring, but spores are not de- 
stroyed (48). 

Pasteurized milk will seldom sour, but unless the milk 
is cooled the spores will germinate and produce bacteria 
that will attack the proteids of the milk, and it is the 
products of some of these bacteria that are thought to be 
poisonous. These spores cannot grow in sweetened con- 
densed milk (46), because it is too concentrated (5 1 ). 

A very convincing demonstration of the presence and 
effect of spores in milk is as follows : 

Take four test-tubes of fresh milk ; to one add a little 
dried cow's manure ; to another a little dust from a city 
street. Boil both of these and also a tube of the natural 
milk. Plug all four with cotton and set them in a cup of 
tepid water. The unboiled milk will probably sour in a 
few hours. The plain boiled milk may not change for 
days, while that with the cow's manure or dust will proba- 
bly curdle without the production of acid in ten or twelve 
hours, owing to the development of spores into bacteria 



102 INFANT FEEDING. 

that attack the proteids of the milk. For this reason 
boiled milk sometimes gives off an extremely offensive 
odor if kept for any length of time. If milk is to be made 
absolutely sterile it must be heated several times, with in- 
tervals between, to allow the spores to germinate so that 
they can be killed by subsequent heatings. 

It will be seen that neither pasteurization nor ordinary 
sterilization will enable milk to be kept for any great 
length of time without cooling, so these processes simply 
allow of a little more carelessness in the handling of milk 
during and after milking, and put off for a few hours the 
changing of the milk. In Europe pasteurization is 
commonly used, for reasons explained in another 
place (65). 

Home pasteurization of milk is often of great value, as 
the milk is usually consumed before the spores have time 
to germinate and affect the milk (140). 

63. Chemical Preservatives. — Many chemical sub- 
stances have the power of preventing the growth of bac- 
teria, and are often put in the milk by milkmen to prevent 
its souring. While contrary to law in most States, the use 
of these preservatives is not uncommon, as they save the 
expense of keeping the milk clean in the first place, the 
cost of pasteurizing and of the ice necessary to keep the 
milk cool, and besides the milk appears to families to be of 
exceptionally good keeping quality. 

The following analyses and comments taken from the 
Year Book of the Department of Agriculture for 1900 will 
prove instructive in connection with chemical milk and 
food preservatives. 

Dry Antiseptic. — Boric acid, 77.2 percent; dry borax 



PRESERVATION OF MILK. 103 

equivalent to 42.98 per cent of crystallized borax. Direc- 
tions : One ounce to ten pounds sausage or to four gal- 
lons milk. 

Iceline. — A 1.92-per-cent solution of formaldehyde. 
Second analysis : A 3.66-per-cent solution formaldehyde. 
Directions: A tablespoonful to ten gallons of milk; one 
and one-half to two times as much to cream and butter- 
milk. A tablespoonful to each gallon of cream intended 
for cream puffs. 

Freezine. — Liquid containing 5.19 per cent formalde- 
hyde. Second analysis: Liquid containing 2=52 per cent 
formaldehyde. Directions: One tablespoonful to ten gal- 
lons of milk, six and two-thirds gallons of cream or butter- 
milk, or three and one-half gallons of ice cream; one 
tablespoonful to each gallon of cream intended for cream 
puffs. 

Preserving Salts. — Six samples, Nos. 1 to 6 inclusive, 
are offered for different classes of foods and sold at differ- 
ent prices, but are identical in composition. They con- 
tain about 30 per cent of borax and 10 per cent of salt. 
Directions: From three to four ounces to one hundred 
pounds of food. 

" A" Preservaline. — Percentage composition: Borax, 
68; salt, 32. Second analysis: Borax, 75 ; salt, 19. Di- 
rections : Mix one-half pound with one hundred and fifty 
pounds of chopped meat ; dust one pound over five hun- 
dred pounds of fresh meat; immerse poultry, drawn or 
undrawn, in a solution of one-quarter pound in two gal- 
lons of water for ten minutes. 

Cream Albuminoid. — 50.4 per cent boric acid, mixed 
with some proteid body, apparently gelatin (see 45). 



104 INFANT FEEDING. 

No Ice Needed " J/" Preservaline. — A four-per-cent 
solution of formaldehyde. 

Special" M" Preservaline. — Solution containing 1.99 
per cent formaldehyde. 

Patent " M" Preservaline. — The sample contained 
83 per cent of boric acid and 17 per cent of borax. 

Milk Sweet. — A 3.90-per-cent solution of formaldehyde. 
A 10-per-cent solution of formaldehyde. 

Ozone Antiseptic Compound. — The sample contained 
51 per cent of boric acid and 72 percent of borax, the 
high total (123) being due to partial dehydration. Direc- 
tions: A tablespoonful to twenty or thirty quarts of milk 
or ten pounds of butter or cheese. 

" Preservative '." — Sodium sulphite, 65 per cent; so- 
dium sulphate, 34 per cent ; colored with an aniline dye. 
Directions: One ounce to fifty pounds of chopped meat. 

"It will be noticed that some preservatives have been 
examined by different analysts with widely varying results, 
indicating that the composition of some commercial prep- 
arations is not constant. One preservative was found to 
consist largely of salicylic acid in 1897 and of benzoic acid 
in 1900. 

" The wide-spread use of these preparations is sug- 
gested by a case recently reported, where a preserving fluid 
had been added to milk first by the farmer, then by the 
collector to whom he sold, again by the wholesale dealer 
in the city, and finally by the retail dealer who delivered 
it to the consumer. The facts were developed by an 
investigation occasioned by the illness of children who 
drank the ' doctored ' milk." 

According to Bigelow: "A pound of meat treated 



PRESERVATION OF MILK. 105 

according to directions with a boric-acid preservative will 
contain from five to nineteen grains, while an infant who 
is fed each day a quart of milk so treated will receive 
eight grains, or a fair-sized dose for an adult." He also 
states that the use of formaldehyde " as a food preserva- 
tive dates back to about 1895." • • • " Not only does it in- 
terfere with digestion to a marked extent, but it has been 
definitely proved that a compound is formed with the 
casein of milk which causes the latter, when treated with 
dilute acid such as exists in the gastric juice, to separate 
in hard lumps that are attacked only with difficulty by 
digestive ferments. The addition of formaldehyde to milk 
has become only too common, and, considering the fact 
that other and less objectionable preservatives will accom- 
plish the same object, its use should be condemned in 
unqualified terms." Formaldehyde is the basis of many 
embalming fluids. 

64. Filtration and Clarification of Milk. — Attempts 
have been made by enterprising milk dealers to improve 
their milk by filtering to remove dirt. The appearance of 
the milk is improved, as no sediment deposits if the milk 
stands for some time, but little or no effect is had in re- 
ducing the bacterial count. 

Clarified milk was advocated for a time, it being 
cleaned or clarified by being passed through a separator 
which threw the foreign matter out as " separator slime " 
(44)- This improves the milk in cleanliness, but breaks 
up the natural emulsion of the fat (42), interferes with 
cream rising, and changes the physical character of the 
milk. Babcock, after three years' experimenting with this 
process, stated: "Although cleaning milk with a separa- 



I0 6 INFANT FEEDING. 

tor has not accomplished all that we had hoped in the 
treatment of milk for cheese, we feel that it has been of 
great benefit, as it has in nearly every case improved the 
quality of the cheese, and the improvement has been 
more marked with tainted milks than with those in good 
condition." 




Fig. 30— Milk Filter. 

Filtered and clarified milks must be kept cool, or they 
will spoil as well as uncleaned milk. 

65. Cleanliness and Low Temperatures —\i no bacte- 
ria found their way into milk it would remain unchanged 
indefinitely, except for the action of the enzymes natural 
to all milks (32 B). But no matter how much care is ex- 
ercised, some bacteria will get into milk. If the tempera- 



PRESERVATION OF MILK 107 

ture is kept below 45 ° F., they will not grow and affect 
the milk, and by the free use of ice it is possible to keep 
clean milk for several weeks in good condition. Without 
the use of ice even pasteurized milk will soon change. 
By care in producing milk the number of bacteria can be 
kept as low as that of commercial pasteurized milk (61). 
Thus, as far as keeping qualities go, this natural milk is 
as good as the pasteurized milk and much better in that 
no changes have been produced by heating. Milk con- 
taining large numbers of ordinary dairy bacteria will keep 
better and be better if ice is used, than if pasteurized and 
no ice is used to keep it cool afterward ; but will spoil 
sooner than pasteurized milk if neither is iced. 

In Europe, pasteurization is conducted by milk com- 
panies on a large scale, as ice is not used as in America. 
According to figures obtained through the United States 
Department of State, the estimated annual consumption 
of ice in England is 450,000 tons (long) and in London 
160,000 tons, while Paris consumes about 65,000 tons. 
New York is thought to use 3,000,000 tons, and Chicago 
2,000,000 tons of ice annually. The London Daily Mail, 
June 21, 1900, speaking of ice in London, says: "The 
demand is rapidly increasing now that the public have 
awakened to an intelligent appreciation of the cheapness 
and usefulness of the commodity." 

66. At the Paris Exposition of 1900 there was an ex- 
hibit of American dairy products in charge of Maj. H. 
E. Alvord, chief of the Dairy Division of the United 
States Department of Agriculture. Among the articles 
exhibited was fresh milk and cream in bottles shipped 
regularly every two 01 three weeks from farms in Illinois. 



108 INFANT FEEDING. 

New Jersey, and New York. To quote Major Alvord's 
report : 

" Foreign visitors and expert milk dealers on the jury 
were hard to convince that nothing but 'cleanliness and 
cold ' were used to preserve these products. . . . When 
finally satisfied as to the honesty of these exhibits, all 
three were promptly awarded gold medals. . . . No other 
country except France attempted to show natural milk 
and cream. The French exhibits of natural milk and 
cream were in striking contrast with those from the Unit- 
ed States. At the July show there was not a single one 
of these local exhibits which was fit to use the day after 
reaching the grounds, and even in the moderate tempera- 
ture of the May and September shows, the French prod- 
ucts were all sour on the second or third day. But there 
were the natural products from America, just as they 
would be delivered to consumers in New York and Chi- 
cago, still perfectly sweet, a fortnight after being bottled 
and after a summer journey of three thousand or four 
thousand miles." 

In a personal letter to the author, Major Alvord states: 
" The general milk service of Europe in all particulars is 
inferior to our own. This is especially true in France, 
where it is difficult to get natural milk, in the cities and 
larger towns, which will remain sweet even a few hours. 
Moreover, we are making more rapid and substantial im- 
provements in this important branch of pure food supply 
than anywhere else in the world." 

It will be seen that the milk business is not conducted 
on the same basis in Europe as in America. Therefore 
quotations and recommendations for pasteurization of 



PRESERVATION OF MILK. 109 

milk made by European observers have not much appli- 
cation in America. 

There can be little doubt in the reader's mind as to 
which method of preserving milk is the best to follow. 
In the next chapter will be given a description of the 
methods of conducting the milk business in American 
citieso 



CHAPTER XIII. 

MARKET MILK. 

67. The great reduction in infant sickness and mor- 
tality that has generally followed an improvement in the 
milk supplies of a community makes a knowledge of the 
proper methods of producing and marketing milk of the 
greatest importance to physicians, sanitarians, and those 
having the care and feeding of infants. 

What is wanted is a plentiful supply of fresh milk 
which is in practically the same condition as it was in the 
cow's udder as far as contamination is concerned, and at 
a price that will put it within the reach of all. It impossi- 
ble to obtain such milk anywhere and at a trifling advance 
over the price charged for ordinary good milk, but not 
without some improvement in the methods of handling it. 

In the previous chapter it was shown that most of the 
changes in milk are caused by bacteria that get into the 
milk (1) with dust and dirt during milking, and (2) from 
dirty dairy utensils after milking, and (3) that the great 
increase in numbers is the result of the milk not being 
cooled and kept cool; (4) also that the bacteria which 
produce poisons in milk are apt to come from stable filth, 
and that these can be kept out of the milk by having the 
cows, milker, and stable in a sanitary condition. 

68. No idea of the conditions under which milk is 
produced or of the number of bacteria it contains can be 



MARKET MILK. in 

obtained by looking at it or even by tasting of it. Milk 
that would cause acute illness may not look or taste dif- 
ferent from wholesome milk. It has been found, how- 
ever, that milk containing few bacteria cannot be pro- 
duced except under the most sanitary conditions; so 
counting the number of bacteria in a specimen of milk 
will tell whether the milk was properly cared for or not. 
If natural milk (60) contains few bacteria, it was pro- 
duced under sanitary conditions and kept cool. If it 
contains large numbers, it is dirty or was not properly 
cooled, or both. 

Unfortunately the counting of bacteria in milk can be 
done only by those especially trained, and is expensive 
work. The inability of the average person to determine 
the condition of milk has led to the organization of milk 
commissions, usually made up of disinterested medical 
men, who set a standard of wholesome milk and issue a 
certificate to any milkman whose milk is up to this stand- 
ard, which he puts on his milk bottles. The purchaser is 
then sure of the quality of his milk. The idea of a milk 
commission originated with Dr. H. L. Coit, of Newark, 
N. J., and has been applied to one dairy near Newark 
with great success. This dairy is under the control of 
the commission in all of its details, and a high price, fif- 
teen cents per quart, is charged for the milk. The popu- 
lation in the territory served by this dairy is as a whole 
well-to-do and can support it. In other sections of the 
country such a high price might be prohibitory and the 
conditions not suitable for such a dairy organization. In 
a large city a great many dairies would be needed to sup- 
ply enough milk, and to organize special dairies would 



ii2 INFANT FEEDING. 

be out of the question. Improvement can best be ac- 
complished by working with milk dealers already estab- 
lished. An idea of how this may be clone can be had 
from a short history of the organization of the Milk Com- 
mission in New York City. 

For several years the author had been studying the 
milk supply of New York in connection with the subject 
of home modification of milk for infant feeding. To get 
an idea of how the milk business of the city was con- 
ducted, a business directory was taken and the financial 
rating of each milkman looked up. The bulk of the busi- 
ness was found to be in the hands of a few dealers — about 
fifty — some of whom were rated by the commercial agen- 
cies as having over $1,000,000 invested. These dealers 
handled about 1,250,000 quarts of milk daily. 

A list of questions was sent to each of them, asking, 
among other things, if they sold milk to families in bot- 
tles or not, and at what price ; under what conditions their 
milk was produced, and what percentage of fat it con- 
tained. From these answers and talks with the milkmen 
who called, the condition of the milk trade was easily dis- 
covered. It appeared that very few of the dealers had 
their own cows, but bought their milk from farmers. 
Mi Ik- receiving stations called creameries are established 
at the railroad stations in dairy sections, and a number of 
farmers bring their milk to these stations, where it is 
mixed and prepared for shipment. 

The milk business is divided sharply into two 
branches: (1) One selling milk in forty-quart cans to gro- 
cery stores, restaurants, etc.; and (2) the other in bottles 
to families direct. 



MARKET MILK. 



113 



(1) Price is the first consideration in " grocery milk," 
and the milk is bought of the farmers at prices that barely 
pay for the cow's feed (7 2 ). The milk is then standard- 
ized — that is, adjusted so that it will contain as nearly as 
possible three per cent of fat and twelve per cent of total 
solids, the minimum quantities allowed by law, any excess 




Fig. 31.— Milk Receiving Station or Creamery. 

of fat being removed and sold as cream. " Grocery milk " 
retails in New York at from four to five cents per 
quart. 

(2) For the milk intended for family trade the farmers 
receive better prices and more care is expended on it. 
Some dealers filter or clarify it (64). Others allow the 
cream to rise and draw off some of the under milk, so 



H4 



INFANT FEEDING. 



that the remaining milk will show more cream when de- 
livered in bottles to the families. 

The milk is then bottled by machinery and packed in 
cases containing cracked ice. Much of this milk is good ; 
some of it all that could be desired. The average retail 
price charged is eight to ten cents per quart. 




Fig. 32.— Bottle Filler. 



Many of these dealers have spent considerable sums 
of money trying to improve their milk, but often they 
have not worked intelligently, not knowing where to ex- 
pend to the best advantage. It is not to be expected that 
they would know how, as many started as drivers of milk 
wagons and know nothing of bacteriology or practical 
sanitation. 



MARKET MILK. 115 

69. Having this information, the writer read a paper 
on " How the Milk Supply of New York May be Im- 
proved," at a meeting of the Medical Society of the 
County of New York, to which the milkmen were invited. 
At this meeting M.aj. H. E. Alvord, chief of the Dairy 
Division of the United States Department of Agricul- 
ture, and Prof. H. W. Conn spoke of dairy conditions and 
bacteriology, and the milkmen presented their side of the 
question. 

A committee, with the author as chairman, was ap- 
pointed to look into the milk-supply question, and the 
present milk commission resulted. Details of the inves- 
tigations conducted by this committee will be found in 
the Medical Record, October 19th, 1901. 

The milk dealers were invited to meet with the com- 
mittee, and many did. The committee explained the ob- 
ject of the movement and asked them how, in their opin- 
ion, the problem could be best attacked. The dealers 
soon found that the object was to help them and not to 
harass or burden them with unnecessary restrictions, 
and they took hold with hearty good- will. The standard 
determined on for milk for certification was not over 
30,000 bacteria per cubic centimetre, acidity not over .2 
per cent, and at least 3.5 per cent of butter fat. This is 
a high standard when it is considered that some of the 
milk has to be brought several hundred miles by railroad 
during hot weather. At first none of the dealers could 
supply milk up to the standard, but by visiting the farm- 
ers who produced the milk and showing them how to ar- 
range their stables, clean their cows, hands, and dairy 
utensils, it was found that milk well within the standard 



u6 



INFANT FEEDING. 



could be produced in abundance and at a small advance 
in price over that of the ordinary bottled milk. 

70- Here is a practical example of progression in 
methods of handling milk, furnished to the author by a 
large New York milk company. The manager of this 
company originally started with 
a single milk wagon and de- 
livered milk to families himself, 
dipping it out of cans. As 
bottled milk began to be han- 
dled, he and other small deal- 
ers combined and established 
creameries or bottling stations 
(68), and now have a large 
business with families. This 
company has several bottling 
stations, at each of which the 
milk of about twenty farmers 
is mixed and bottled. 

By experience it had been 

found that the milk could not 

arrive in New York in good 

condition unless cooled soon 

after milking, so no milk would 

be received from the farmers 

that was warmer than 6o° F. The cooling was clone by 

pouring the milk over the surface of a cooler containing 

well or spring water. 

One day in the middle of August, 1 901, the bacteria 
in the milk of each farmer that supplied one of these 
creameries were counted ; the farmers were then shown 




Fig. 33.— Milk Cooler for Use with 



MARKET MILK. 



ii7 



how, by cleaning out their stables better, wiping the cows 
with a damp cloth, and keeping dusty hay out of the sta- 
ble during milking time, the bacteria in the milk would 
be reduced in numbers; and two or three weeks later an- 
other count was made. Here are the counts before any 
suggestions were made, and after they were put into 
effect. In some instances remarkable reductions in 
count are shown. It cost no more to produce the milk 
at one time than the other. 

Bacteria per Cubic Centimetre. 



Farmer. 


Before changes were made. 
Middle of August. 


After changes were made. 
About September 1st. 


No. i 


44, Soo 

83,400 morning. 
38,400 night. 
65,000 

32,000 

57,600 morning. 
70,400 night. 
460,800 

578,000 
76,800 
63,500 

102,400 

137,000 

99,300 

9,827,000 

121 , 600 

80,000 

76,800 
159,200 
349,200 


29,300 morning. 

23,600 night. 

41,400 morning. 

37,200 night. 

32,000 morning. 
321,000 night. 

32,000 morning. 
215,000 night. 

12,000 morning. 
172,000 night, 

15,000 morning. 

47,200 night. 
110,200 morning. 

31,400 night. 

27,700 morning. 

59,100 night. 

10,200 morning. 

19,200 night. 

18,900 morning. 

19,200 night. 
44,800 






No. 4 


No. 5 




No. 7 , 


No. 8 




No. io 

No. ii 






21,300 morning. 
64,000 night. 
26,700 morning. 
12, Soo night. 
210,400 morning. 
S3, 200 night. 
518,400 




No. 15 






No. 1 8 , 


21.400 morning. 
25,600 night. 





n8 INFANT FEEDING. 

One of these farmers was selected to produce milk for 
certification, and here are the counts of his milk when 
taken from the delivery wagon in New York: 

1901 — December 37, 100 

December 17,000 

December 26,000 

December 36,000 

I902 — January 19,000 

January 11 ,000 

January 72,000 

January 96,000 

February 1 50,000 

February 1 7,000 at farm. 

February 450,000 at creamery. 

February 12,000 

February 7, 750 

February 2, 700 

March 3,450 

March 3, 700 

March 4.750 

March 41,000 

April 4, Soo 

April 4,000 

April 5,200 

April 11,000 

May 1 ,000 

May 20,000 

May 5, Soo 

May 1 7,000 

June 12,900 

June 11,500 

The high counts of January and February were found 
to be caused by a little water, used in washing the bottles 
at the creameries, remaining in the bottles. After the 
bottles were sterilized by steam before being filled the 
count became low. The one high count in March was 
found to be caused by laying a new floor in the creamery. 
Eternal vigilance is the price of low bacterial count. 

The average price the farmer received for this milk 



MARKET MILK. 



119 



during nine months was 3.53^ cents per quart. During 
June, 1 901, the price was 2.57^ cents, and during No- 
vember, December, and January, 1902, 4.06^ cents. The 
other farmers saw he was making money, and wished to 
be allowed to furnish extra clean milk as fast as it could 
be sold in New York. Two cents a quart above the prices 
these farmers receive for their ordinary milk, which is 




Fig. 34.— Bottle Sterilizer. 



used for bottling, will enabled them to produce "certi- 
fied milk." It is a mistake to imagine that costly stables 
are necessary. Such milk can be produced in the barn of 
any progressive farmer. 

Undoubtedly hospitals and institutions could make 
yearly contracts for this milk at five cents per quart in 
bulk and at seven cents in bottles. If enough demand 
could be created from the general public, so the extra 
expense of delivering small lots would be reduced, it 



120 INFANT FEEDING. 

would not sell at fifteen cents, the price charged, but at ten 
cents per quart, the present price for good bottled milk 
in New York. In small towns and cities it could be sold at 
six cents, as the freight charges into New York are about 
one cent a bottle, and these would be unnecessary when 
the milk was produced near by. * 

71. Gi'ocery Milk. — It is almost hopeless to try to im- 
prove " grocery milk," as no one in particular is responsi- 
ble for it. The price the farmer receives for it (72), 
barely covering cost of the cow's feed, prohibits exercise 
of the necessary care on his part, and the continual open- 
ing of the milk can in the grocery store makes easy the 
entrance of germ-laden dust (62). The transportation 
from the farmer to the store is obtained at the lowest 
price, so that conditions preventing bacterial growth can- 
not be had. Legislation cannot compel a farmer to pro- 
duce his milk at a loss, and the population that consumes 
" grocery milk " would vote out of office authorities that 
prohibited its sale or advanced its cost. Large numbers 
of ordinary dairy bacteria in milk are not harmful to 
adults. Buttermilk contains millions of them to the tea- 
spoonful, and no one is afraid to drink it. The great ma- 
jority of adults would rather run the risk of using " gro- 
cery milk" than pay double price for "certified milk" 
with its to them slightly increased safety. With infants, 
the increase of safety by using " certified milk" is very 
great, and few parents would let three or four cents a day 
additional cost prevent their purchasing it for their chil- 
dren, if they knew its value. 

*The general advance in prices of labor and feeds during the past few- 
years has caused increases in cost of all kinds of milk, and certified milk 
will not be obtainable at much less than fifteen cents per quart (1908). 



MARKET MILK. 121 

72. Cost of Producing Milk. — The full force of the 
statements concerning " grocery milk " will be appreciated 
by a glance over the following figures, showing what 
farmers receive, and the cost of producing a quart of milk, 
also the profit the farmer is liable to make from a cow 
during a year. 

According to the New York Farmer, a dairy paper, 
the average prices the farmers of New York State have 
actually received for the milk shipped to New York in 
forty-quart cans have been during 



Cents 
per quart. 

I897 I.69I-I.84I 

1898 I. 735-I. 885 

1899 I.879-2.O29 



Cents 
per quart. 

I90O 2.084-2. 237 

I9OI 1.969-2.120 



and the prices paid by one of the largest milk-condensing 
companies, which requires a fairly clean milk, were dur- 
ing 1 901: 



Cents 
I 9° I " per quart. 

January 3 33X 

February 3 1 1 ^ 

March 2 90X 

April 2.47X 

May 2. 15 

June 1. 72 



Cents 
«9° x - per quart. 

July ..'.'.. 2.04^ 

August 2. 36^ 

September 2. 79^ 

October 3.01 

November 3. 22^ 

December 3. 33^ 



Now glance at the cost of producing milk.* 
73- The average cost of the milk of a herd of twenty 
cows at the New York (Cornell) Experiment Station for 
a year was .625 cents per one hundred pounds, or 1.33 
cents per quart. The milk of one cow cost $1.48 per one 
hundred pounds, or 3.15 cents per quart. 

Tests of pure-bred cattle at the Maine, New York, 

* See foot note on opposite page. The disproportion between cost and 
selling price still exists (190S). 



INFANT FEEDING. 



and New Jersey experiment stations show the following 
costs : 



Breed. 


Average 

yield per year 

in pounds. 


Average 
per cent, of 


Cost of 100 

pounds milk. 

Cents. 


Cost 
per quart. 




8,696 
8,215 
6,909 
6,2IO 

5,579 
3,9S4 


3-97 
3-43 
3.60 
5.20 
5-40 
4.60 


7S.7 
74-7 
7S.5 

S2.S 

94-7 

94.0 


1.66 


Holstein Friesian 


1.59 
1.67 
1.76 








2.05 





Individual cows of the herd of the Wisconsin Experi- 
ment Station made the following showing during the year 
1900: 



Grade Short Horn 10,131.74.7 39.60 39.0 0.83 92.23 79.86 

Grade Short Horn 10,100.04.15 36.44 36.0 .76 74.00 54.43 

Grade Short Horn 7,833.040 38.19 48.7 1.03 41.06 Not given. 

Grade Short Horn 6,973.24.2 27.16 39.1 .83 47.27 Not given. 

Grade Short Horn 7,996.74.1 26.22 32.7 .70 57.48 20.86 

Grade Jersey 5,775-3 5-7 32. 18 56.1 1.20 49.32 Not given. 

Grade Jersey 7,473-0 5-3 32.27 43.1 .92 66.20 57.14 

Grade Guernsey 6,095.05.5 26. 89 44.1 .94 57.03 .07 

Holstein Friesian 9,561.43.5 38.21 39.0 .83 52.30 Not given. 

Holstein Friesian 8.868.9 3. S .17-39 42.1 .90 54-o8 Not given. 











, 




0. 


^ £ 
&. 


8j3 

c Q 


U 2^ 


1 |e 

°feU 

0. 


S p §• 
> 5." 


10,131.7 


4-7 


39.6o 


39.0 


O.83 


92.23 


10,100.0 


4.15 


36.44 


36.0 


-76 


74.00 


7,833-0 


4 


38.19 


48.7 


I.03 


41.06 


6,973.2 


4.2 


27.16 


39-i 


• S3 


47.27 


7,996.7 


4-i 


26.22 


32-7 


.70 


57.48 


5,775.3 


5-7 


32.18 


56.1 


1.20 


49-32 


7,473.0 


5-3 


32.27 


43-i 


.92 


66.20 


6,095.0 


5-5 


26.89 


44-1 


•94 


57.03 


9,561.4 


3-5 


38.21 


39-0 


•8.3 


52.30 


8.868.9 


3-8 


37-39 


42.1 


.90 


54.08 



These ten cows netted $590.97, or $59.09 per cow dur- 
ing a year, or 16 cents a day. In the foregoing costs of 
milk, no allowance is made for labor, the cow's manure 
being said to be worth her care. 

It has been stated by H. E. Alvord that many authori- 
ties believe that in the United States one-third of the 
cows are kept at a loss, one-third about pay for them- 
selves, and one-third pay a profit to their owners. If at 
the experiment stations, the most scientific dairymen, with 
selected stock, which produce milk at less than one cent 



MARKET MILK. 123 

a quart, can show a yearly profit of only $59.09 per cow, 
the other experiment station herds whose milk-cost 
ranged from 1.55 to 2.9 cents per quart would not have 
paid expenses with the same prices for their products. 
At the New York Experiment Station (Geneva) it was 
calculated the herd would pay $19.80 per cow, if milk 
sold at 2 Y\ cents per quart. 

With these costs and profits obtained by experts with 
selected cows, what can be the ordinary farmer's profits 
at the prices he receives ? 

Farrington, reporting on a herd of twelve cows tested 
on a farm for a year by experts from the Wisconsin Ex- 
periment Station, says : " The entire herd only paid a 
profit of $75, and three of the twelve cows paid $50 of this 
amount, while the combined profit of the other nine was 
only $25. . . . There were three cows which did not pro- 
duce milk enough to pay for their feed." The daily 
profit each cow paid was one cent. 

Farmers cannot be expected to take additional care of 
their milk without extra compensation. Higher prices to 
the farmer is the solution of the milk problem, and the 
dealer should also have extra compensation for any addi- 
tional labor and care on his part. 

74. Milk Commission's Regulations. — Every milk 
commission will have to adapt its regulations to local con- 
ditions. No better guide can be followed than the " Fifty 
Dairy Rules"* of the United States Department of Agri- 
culture. 

The following circulars sent out to the milkmen by 

* A copy of these can be had free of charge by applying to the Secretary of 
Agriculture, Washington, D, C. 



124 INFANT FEEDING. 

the New York Commission may prove interesting. It 
will be noticed that the cost to the dealers for examina- 
tion of their milk is as low as one-tenth of one cent a 
quart, and will be lower as the output increases. 

CIRCULARS, 
ist. "Certified Milk." 

CIRCULAR OF INFORMATION CONCERNING THE REQUIRE- 
MENTS OF THE MILK COMMISSION OF THE MEDICAL 
SOCIETY OF THE COUNTY OF NEW YORK FOR "CER- 
TIFIED" MILK. 

The Commission appointed by the Medical Society of the 
County of New York to aid in improving the milk supply of New 
York City invites the co-operation of the milk-dealers and farm- 
ers in attaining that end. The sale of pure milk is of advantage 
to those furnishing it, as well as to those who use it. The Com- 
mission has undertaken to assist both consumer and producer by 
fixing a standard of cleanliness and quality to which it can certify, 
and by giving information concerning the measures needful for 
obtaining that degree of purity. 

The most practicable standard for the estimation of cleanliness 
in the handling and care of milk is its relative freedom from bac- 
teria. The Commission has tentatively fixed upon a maximum of 
30,000 germs of all kinds per cubic centimetre of milk, which 
must not be exceeded in order to obtain the indorsement of the 
Commission. This standard must be attained solely by measures 
directed toward scrupulous cleanliness, proper cooling, and prompt 
delivery. The milk certified by the Commission must contain not 
less than four per cent, of butter fat, on the average, and have all 
other characteristics of pure, wholesome milk. 

In order that dealers who incur the expense and take the pre- 
cautions necessary to furnish a truly clean and wholesome milk 
may have some suitable means of bringing these facts before the 
public, the Commission offers them the right to use caps on their 



MARKET MILK. 125 

milk jars stamped with the words, " Certified by the Commission 
of the Medical Society of the County of New York." The dealers 
are given the right to use these certificates when their milk is ob- 
tained under the conditions required by the Commission and con- 
forms to its standards. 

The required conditions are as follows : 

1 . The Barnyard. — The barnyard should be free from manure 
and well drained, so that it may not harbor stagnant water. The 
manure which collects each day should not be piled close to the 
barn, but should be taken several hundred feet away. If these 
rules are observed not only will the barnyard be free from objec- 
tionable smell, which is always an injury to the milk, but the 
number of flies in summer will be considerably diminished. These 
flies in themselves are an element of danger, for they are fond of 
both filth and milk, and are liable to get into the milk after having 
soiled their bodies and legs in recently visited filth, thus carrying 
it into the milk. Flies also irritate cows, and by making them 
nervous reduce the amount of their milk. 

2. The Stable. — In the stable the principles of cleanliness 
must be strictly observed. The room in which the cows are milked 
should have no storage loft above it ; where this is not feasible, 
the floor of the loft should be tight, to prevent the sifting of dust 
into the stable beneath. The stables should be well ventilated, 
lighted, and drained, and should have tight floors, preferably of 
cement. They should be whitewashed inside at least twice a year, 
and the air should always be fresh and without bad odor. A suffi- 
cient number of lanterns should be provided to enable the neces- 
sary work to be properly done during dark hours. There should 
be an adequate water supply and the necessary wash-basins, soap, 
and towels. The manure should be removed from the stalls twice 
daily, except when the cows are outside in the fields the entire 
time between the morning and afternoon milkings. The manure 
gutter must be kept in a sanitary condition, and all sweeping and 
cleaning must be finished at least twenty minutes before milking, 
so that at that time the air may be free from dust. 

3. Water Supply. — The whole premises used for dairy pur- 
poses, as well as the barn, must have a supply of water absolutely 



126 INFANT FEEDING. 

tree from any danger of pollution with animal matter, and suffi- 
ciently abundant for all purposes and easy of access. 

4. The Cows. — The cows should be examined at least twice 
a year by a skilled veterinarian. Any animal suspected of being 
in bad health must be promptly removed from the herd and her 
milk rejected. Never add an animal to the herd until it has been 
tested with tuberculin and it is certain that it is free from disease. 
Do not allow the cows to be excited by hard driving, abuse, loud 
talking, or any unnecessary disturbance. Do not allow any 
strongly flavored food, like garlic, which will affect the flavor of 
the milk, to be eaten by the cows. 

Groom the entire body of the cow daily. Before each milking 
wipe the udder with a clean clamp cloth, and when necessary wash 
it with soap and clean water and wipe it dry with a clean towel. 
Never leave the udder wet, and be sure the water and towel used 
are clean. If the hair in the region of the udder is long and not 
easily kept clean, it should be clipped. The cows must not be 
allowed to lie down after being cleaned for milking until the milk- 
ing is finished. A chain or rope must be stretched under the 
neck to prevent this. 

All milk from cows sixty days before and ten days after calv- 
ing must be rejected. 

5. The Milkers. — The milker should be personally clean. 
He should neither have nor come in contact with any contagious 
disease while employed in milking or handling milk. In case of 
any illness in the person or family of any employee in the dairy, 
such employee must absent himself from the dairy until a physician 
certifies that it is safe for him to return. 

Before milking, the hands should be thoroughly washed in 
warm water with soap and a nail brush and well dried with a 
clean towel. On no account should the hands be wet during the 
milking. 

The milking should be done regularly at the same hour morn- 
ing and evening, and in a quiet, thorough manner. Light-colored 
washable outer garments should be worn during milking. They 
should be clean and dry, and when not in use for this purpose 
should be kept in a clean place protected from dust. Milking 



MARKET MILK. 127 

stools must be kept clean. Iron stools, painted white, are recom- 
mended. 

6. Helpers other than Milkers. — All persons engaged in 
the stable and dairy should be reliable and intelligent. Children 
under twelve years should not be allowed in the stable during 
milking, since in their ignorance they may do harm, and from 
their liability to contagious diseases they are more apt than older 
persons to transmit them through the milk. 

7. Small Animals. — Cats and clogs must be excluded from 
the stables during the time of milking. 

8. The Milk. — The first few streams from each teat should 
be discarded, in order to free the milk ducts from milk that has 
remained in them for some time and in which bacteria are sure to 
have multiplied greatly. If in any milking a part of the milk is 
bloody or stringy or unnatural in appearance, the whole quantity 
of milk yielded by that animal must be rejected. If any accident 
occurs by which the milk in a pail becomes dirty, do not try to 
remove the dirt by straining, but reject all the milk and cleanse 
the pail. The milk pails used should have an opening not exceed- 
ing eight inches in diameter. 

Remove the milk of each cow from the stable immediately 
after it is obtained to a clean room and strain it through a steril- 
ized strainer. 

The rapid cooling of milk is a matter of great importance. 
The milk should be cooled to 45 ° within one hour. Aeration of 
pure milk beyond that obtained in milking is unnecessary. 

All dairy utensils, including bottles, must be thoroughly 
cleansed and sterilized. This can be done by first thoroughly 
rinsing in warm water, then washing with a brush and soap or 
other alkaline cleansing material and hot water, and thoroughly 
rinsing. After this cleansing, they should be sterilized with boil- 
ing water or steam and then kept inverted in a place free from 
dust. 

9. The Dairy. — The room or rooms where the bottles, milk 
pails, strainers, and other utensils are cleaned and sterilized 
should be separated somewhat from the house, or when this is 
impossible have at least a separate entrance, and be used only for 



128 INFANT FEEDING. 

dairy purposes, so as to lessen the danger of transmitting through 
the milk contagious diseases which may occur in the home. 

Bottles, after filling, must be closed with sterilized discs, and 
capped so as to keep all dirt and dust from the inner surface of 
the neck and the mouth of the bottle. 

10. Examination of the Milk and Dairy Inspection. — In 
order that the dealers and the Commission may be kept informed 
of the character of the milk, specimens taken at random from the 
day's supply must be sent weekly to the Research Laboratory of 
the Health Department, where examinations will be made by ex- 
perts for the Commission; the Health Department having given 
the use of its laboratories for this purpose. 

The Commission reserves to itself the right to make inspections 
of certified farms at any time and to take specimens of milk for 
examination. It also reserves the right to change its standards 
in any reasonable manner upon due notice being given to the 
dealers. 

After January i, 1902, the expenses incurred in making the 
regular milk examinations and inspections will be borne by the 
dealers. In fixing the charges each farm or group of farms will 
be considered a unit. The Secretary of the County Medical So- 
ciety will send bills to the dealers about the middle of each month. 
Prompt payment is requested. \ 

The monthly charges, which are intended to cover all expenses, 
will be as follows : 

For each group of farms sending daily less than 100 quarts $8.00 
" " 100 to 200 " 10.00 

" " 200 to 500 " 12.00 

" " over 500 " 15.00 

2d. "Inspected Milk." 

CIRCULAR OF INFORMATION CONCERNING THE REQUIRE- 
MENTS OF THE MILK COMMISSION OF THE MEDICAL 
SOCIETY OF THE COUNTY OF NEW YORK FOR "IN- 
SPECTED" MILK. 

The Commission appointed by the Medical Society of the 
County of New York to aid in improving the milk supply of New 
York City has formulated the following requirements, affecting 



MARKET MILK. 129 

the farms inspected by it and the handling of the milk obtained at 
those farms. The Commission offers those dealers complying 
with these requirements the right to use caps on their milk bottles, 
stamped: "Inspected. Milk Commission Medical Society, 
County of New York." 

The requirements are as follows : 

1. The Barnyard. 

(a) It must contain no manure in summer and none in con- 

tact with the stable in winter. 

(b) It must be well drained and kept reasonably clean. 

2. The Stables. 

(a) The ventilation and light must be sufficient for the num- 

ber of cows stabled, so that the barn shall be light and 
the air never close. 

(b) The floor shall be of wood or cement. 

(c) The ceiling shall be tight, if a loft above is used. 

(d) Basins, hand brushes, clean water, soap and clean towels 

shall be provided in the barn or adjacent dairy room. 

(e) The stable shall be whitewashed in the fall, and in the 

spring if necessary. 

(f) A sufficient number of lanterns shall be provided to allow 

the milking to be carried on properly. 

(g) Clean the ceiling and sidings once a month. 

(h) The bedding shall be shavings, sawdust, dried leaves, cut 
straw, or other material that meets with the approval of 
the Commission. 

(i) The soiled bedding must be removed daily. 

(j) The manure must be removed daily from the stalls and 
open manure-gutter. If a covered manure-gutter is 
used, it must be kept in a sanitary condition. 

(k) The application of land-plaster or lime on the floor daily 
is recommended. 

(1) Sweep the entire floor outside of the stalls daily at least an 
hour before milking is begun. 

3. Water Supply. 

Pure water must be used for all purposes. It must be 
accessible and abundant. 
9 



£30 INFANT FEEDING. 

4. The Cows. 

(a) Discard milk containing mucus or blood and that from any 

diseased cow. 
(bj Reject milk from any animal forty -five days before and 

six days after calving. 

(c) The food given must be suitable both in amount and kind 

and must not give a disagreeable flavor to the milk. 

(d) Keep the cows clean on flanks, belly, udder, and tail. 

(e) Clip long hairs about udders and clip the tail sufficiently 

to clear the ground. 

(f) The cows must be kept from lying down between the 

cleaning and milking. The best means of accomplish- 
ing this is by throat latches. 

(g) Clean the udder thoroughly before milking. 

5. The Milkers. 

(a) No milker or assistant shall have any connection with the 

milk at any stage of its production if he has any com- 
municable disease, or if he has been exposed to scarlet 
fever, diphtheria, typhoid fever, or smallpox. 

(b) After having everything prepared for milking, thoroughly 

wash the hands with soap, water, and brush, so that they 
may be clean when milking is begun. 

(c) The hands and teats must be kept dry during milking. If 

they become moistened with milk, they must be wiped 
dry with a clean towel. 

(d) Suitable clean outer garments, such as overalls and jump- 

ers, must be put on before milking. : 

6. Utensils. 

(a) Strainers, whether metal, gauze, or cotton, must be abso- 

lutely clean when used for straining milk. 

(b) All dairy utensils must be absolutely clean and free from 

dust. 

7. The Milk. 

(a) The milk must not be adulterated in any way. 

(b) It must average four per cent, of butter-fat. 

(c) Cooling must be begun within thirty minutes after the 

milking. The temperature of the milk must be reduced 



MARKET MILK. 131 

to 55 F. within two hours after milking and to 50 F. 
within three hours and kept below that temperature 
until delivered to the consumer, 
(d) When delivered to the consumer the milk must not aver- 
age over 100,000 bacteria per cubic centimetre from 
May 1 st to September 30th, and not over 60,000 bacteria 
per cubic centimetre from October 1st to April 30th. 
If the Commission's requirements are fulfilled, the bac- 
teria will not be in excess of the number permitted. 

8. Inspections. 

(a) The farms which furnish " Inspected " milk must always 

be open to inspection by the Commission. 

(b) Samples of milk must be regularly submitted for bacterio- 

logical examination once a month. 

For cooling the milk to the best advantage, straining 
through cheese-cloth or a Turkish towel into a can placed 
in ice-water is better than the commercial coolers (70). 
All utensils should be simple, with tight seams (58), and 
steamed if possible before using (58). 

The necessity of rejecting a cow from a herd simply 
because she reacts to the tuberculin test (55) is open to 
doubt.* A difference is now being drawn between tuber- 
culin tuberculosis and clinical tuberculosis. If only a 
small gland is affected the cow will respond to the tuber- 
culin test; the disease may not spread in the body, and 
the cow's milk will not contain tubercle bacilli. When 
clinical symptoms of tuberculosis appear, the cow's milk 
should not be used as food. 

Bacterial Standard for Certified Milk. — In the author's 
opinion thirty thousand bacteria to the cubic centimetre 
is a small enough number to merit certification of milk. 

* The prevailing opinion is that milk from a tuberculin-reacting cow 
should not be used in feeding the infant. 



132 INFANT FEEDING. 

If enough care is taken to keep the number as low as this, 
most putrefactive bacteria will be kept out (54)- The 
precautions necessary to keep below this number greatly 
increase the cost of milk and defeat the object in view, 
viz., to place within the reach of all wholesome milk at a 
moderate price, as few milkmen can keep up to a higher 
standard, no matter what price they obtain, and the high 
price will curtail consumption. 



CHAPTER XIV. 



METHODS OF TESTING MILK. 



75. For most practical purposes it is necessary to de- 
termine only the percentage of fat and solids not fat in 
milk. From (1) the percentage of fat and 
(2) specific gravity, the (3) solids not fat can 
be readily determined. These tests tell 
whether the milk has been watered or 
skimmed or both. 

Fat Test. — The most generally used 
method of testing fat in milk and cream is 
that invented by Dr. S. M. Babcock, of the 
Wisconsin Experiment Station. In this test 
the ingredients of milk other than fat are 
dissolved by sulphuric acid in a special 
bottle with a graduated neck. Hot water is 
added, and the bottle is whirled in a centri- 
fuge until the melted fat rises into the neck, 
when its percentage can be read. 

The necks of the bottles for milk testing 
are graduated from o to 10 per cent, with 
subdivisions of .2 per cent, and contain 2 
c.c. between the o and 10 marks, or 10 per 
cent of 20 c.c. If the milk and melted fat 
had the same specific gravity as water, 20 c.c. of milk 
would be used in making a test. However, 17.44 c.c. of 



i 



Fig. 35 — Babcock 
Milk Test Bottle. 
( Farrington and 
Woll.) 



134 



INFANT FEEDING. 



milk are placed in the bottles, as 2 c.c. of melted butter 
fat weigh but 1.8 grams and 17.44 c.c. of milk weigh ten 
times as much, or 18 grams. The percentage 
reading is thus by weight, not volume. 

Cream bottles are graduated from o to 35 per 
cent, with subdivisions of .5 per cent. A little less 
than 18 c.c. of cream is placed in the bottle, as 
this quantity weighs 18 gm., the excess of fat 
lighter than water offsetting the solids heavier 
than water in the cream. 

In making the test, (1) 
the sample of milk or 
cream is mixed by gently 
pouring from one vessel 
/ \ into another two or three 
times. (2) A pipette grad- 
uated for 17.6 c.c. of milk 
or 18 c.c. of cream is used 

\l jr for measuring, as this de- 
W livers the proper quantities 

into the bottle when the 

last drop is blown out with 

the breath. (3) To the 

milk or cream in the test 

bottle is added about 

17.5 c.c. of commer- 
cially pure sulphuric 

acid, specific gravity, 
1 .82. One cubic centimetre 
more or less makes little difference. The color at the junc- 
tion of the milk with the acid is greenish with pure milk. 



Fig. 36.— 
17.6 c.c. 
Pipette. 

(Farring- 
ton and 
Woll.) 




Fig. 37-— Wrong Way of Emptying Pipette. 
(Farrington and Woll.) 



METHODS OF TESTING MILK. 135 

If formaldehyde is present there is a violet ring and the 
curd dissolves slowly. A ring other than greenish sug- 
gests preservatives. (4) The bottle is now gently shaken 
until all the curd that forms is dissolved, care being taken 
not to allow any specks to get into the neck. The 
mixed milk and acid becomes very hot and melts the 




Fig. 38.— Right Way of Emptying Pipette. (Farrington and Woll.) 

fat. It is always well to make tests in duplicate to 
allow for accidents during the process. (5) The bottles 
are then placed in a centrifuge and whirled for five min- 
utes. (6) Boiling water is added up to the base of the 
neck and the bottles are whirled for a minute or two. 
(7) Again, boiling water is added so the melted butter 



30 



INFANT FEEDING. 



fat will reach nearly to the top mark on the scale, and 
the bottles are again whirled for one minute. (8) Before 
reading the percentage of fat it is well 
to pour some boiling water over the 
outside of the necks of the bottles with 
a pipette to be sure the butter fat is 
melted. If the acid was too strong the 
fat may appear charred, and if too weak 
the curd will not be entirely dissolved. 

In selecting Babcock milk- testing 
machines, those that open by removing a 
cover on the plan of that in 




fig. 39--Aad Measure, the illustration will be found 

(Farrington and Woll.) 

most convenient. 



The glassware should be purchased of 
a dealer who will guarantee its accuracy. 
All dairy supply houses carry these testing 
outfits. 

76. Specific gravity. — Before the inven- 
tion of the Babcock fat test, milk was gen- 
erally tested with a lactometer from which 
its specific gravity could be determined, but 
this test has little or no value by itself. The 
specific gravity of normal milk varies from 
1.029 to 1.035, while that of skimmed milk 
is as high as 1 .036. The presence of the fat, 
which is lighter than water, makes the 
specific gravity of normal milk less than 
that of skimmed milk, the solids of which 
are heavier than water. Milkmen soon found that by 
skimming off the cream and adding water to the skimmed 



— B 

—0 



Fig. 40- — Fat in 
Neck of Test Bot- 
1 1 e . Reading 
should be made be- 
tween A and B not 
between A and C 
(Wing.) 



METHODS OF TESTING MILK. 



137 



milk, the specific gravity of the diluted skimmed milk 
could be made the same as that of normal milk. For 
this reason the lactometer has little value by itself for 
testing milk. But if, in addition to the specific gravity 
obtained from the lactometer reading, the percentage of 
fat is determined, the total solids and solids not fat in a 
specimen of milk can be quickly ascertained. Skimming 
and watering of milk can thus be readily detected. 

There are two forms of lactometers in general use, 
known as the Board of 
Health and Quevenne's 
lactometers. The scale 
on the Board of Health 
lactometer is divided 
into 120 degrees, the 
100 mark indicating a 
specific gravity of 1 .029 
and the 120 mark of 
1.035, which is the range 
for normal milk. As 
100 degrees on the lac- 
tometer scale equal a specific gravity of 1.029, multiplying 
any degree on the scale by .29 will give the specific grav- 
ity figures when 1 .0 is placed to the left of the result. 

The scale on the Quevenne lactometer reads from 15 
to 40, and gives the specific gravity directly by placing 1.0 
to the left of the figures on the scale (77). 

Tables have been published by several chemists which 
show the percentages of solids not fat in milk for each 
half degree of specific gravity and each one-fifth per cent 
of fat, which are exact enough for all practical purposes, 




abcock-Milk Testing Machine. 



INFANT FEEDING. 



being within a small fraction of one per cent of the results 
obtained by weighing the solids. The tables of different 
chemists show slight differences, which 
probably result from the use of different 
methods of analysis and weighing. In 
America the table constructed by Bab- 
cock is largely used. It is not given 
here because the following simple rule 
given by Farrington and Woll makes it 
unnecessary. 

Rule : Divide the lactometer reading 
(Quevenne's scale) by 4, and add to this 
one-fifth of the percentage of fat ; result, 
solids not fat. By adding to this the 
weight of fat, total solids are obtained 
(28). 

77. Hoiu to Use Lactometers. — Mix 
the sample of milk by gently pouring it 
from one vessel into another, so that the 
fat shall be uniformly distributed. Have 
the lactometer dry and lower it gently 
into the milk, preferably in a hydrometer 
jar. Always have the milk at a tem- 
perature within ten degrees of 6o° F. 
Lactometers combined with thermom- 
eters can be had at any dairy supply 
house. Do not allow over half a minute 
to elapse before taking the reading. If 
the Board of Health lactometer is used, 
multiply the reading by .29 to get the Quevenne 
reading. Then for every degree of temperature above 




Fig. 42. — (Quevenne Lac 
tometer Floating in Milk 
(Farrington and Woll.) 



METHODS OF TESTING MILK. 139 

6o° F. add .1 degree specific gravity, and subtract .1 de- 
gree for each degree of temperature below 6o° F. Milk 
should not be tested within three hours of leaving the 
cow, as erroneous results are obtained, the reason for 
which is not known. 

Example. — A specimen of milk is found to contain 
four per cent of fat, and the Board of Health lactometer 
read 114 at 55 F., or no° at 65 F. 

114 X .29 = 33.06- .5 temp, correction = 32.56 ) f Quevenne scale . 
no X -29 = 31.90-}- -5 temp, correction = 32.40 ) 

Place 1 .0 to the left of these results and remove the deci- 
mal point from the degrees, and specific gravity 1.03256 
or 1.0324 is the result. 

Per cent. 
One- fifth of the percentage of fat (4 per 

cent, -f- 5) 0.8 

One-fourth of the Quevenne lactometer reading 

(32.5°-=- 4) + 8. 12 



8.92 solids not fat. 
-f-4.00 fat. 

12.90 total solids. 

This method is accurate for milks containing up to 6 
per cent of fat. 

78. In paragraph 38 will be found complete analyses 
of twenty-nine different lots of mixed milks, ranging by 
slight percentages from 3 per cent to 5.25 per cent of fat 
and 1 1.60 per cent to 14.94 P er cent total solids. 

79- Legal Standards. — In nearly all of the States 
which have dairy laws the legal requirement is that milk 
shall contain at least 3 per cent of butter fat and 1 2 per cent 
of total solids. Some States also require that there shall 
be at least 8 per cent, and others 9.3 per cent of solids not 
fat, as will be seen in the following table: 



140 



INFANT FEEDING. 



State Standards for Dairy Products.* 

In force June, 1900. From Bull. 26, U. S. Dept. Agr. , Bureau of Animal 
Industry. 



District of Columbia 

Georgia 

Illinois ' 

Indiana 

Iowa 

Maine 

Massachusetts 

Massachusetts, Apr. and Sept 
Michigan 

Minnesota 

New Hampshire 

New Jersey 

New York 3 

North Dakota 

Ohio 3 

Ohio, May and June 

Oregon 3 

Pennsylvania 

(Milk and skim-milk standards 

refer to cities of second and 

third classes.) 

Rhode Island 

South Carolina 

Utah 

Vermont 

Vermont, May and June 

Washington 

Wisconsin 



M 


ILK. 




. 




j 








|| 8 


2*2 Jj 
















"d, 


' ep. 


a, 




9.0 


3-5 




8.5 


3-5 


I2.0 




3 




9 


3 


12.5 




3 


12 




3 


13 


9-3 


3-7 


12-5 


9 


3 


12.5 




3 


Sp. gr. 






1.029-33 






13 




3-5 


13 






12 






12 




3 


12 




3 


12 




3 


11. 5 






12 


8 


3 


12.5 




3 


Sp. gr. 






1.029-33 






12 




2.5 




8.5 


3 


12.5 


9.25 




1 2 








8 


3 
3 



Skim-Milk. 

Total solids, 

Per cent. 



9-3 



9-3 
Sp. gr. 1.032-37. 



Sp. gr. 1.038.... 
2.5 p.c. fat, 6 p.c. 

cream by vol. sp. 

gr. 1.032-37. 



9 p. c. solids not 
fat. 






1 Condensed milk shall be made from milk containing at least the legal stand- 
ard of three per cent of butter fat and evaporated to one third or less of its 
original volume. 

2 Coffee cream shall contain at least fifteen per cent of fat and whipping 
cream twenty-two per cent fat. 

3 Milk solids of condensed milk shall be in quantity the equivalent of twelve 
per cent of milk solids in crude milk, of which twenty-five per cent shall be fat. 

* Since the passage of the National Pure Food Law in 1906 the laws of 
the different States have been undergoing changes, and it is probable that 
eventually the food laws will become uniform throughout the United States. 



METHODS OF TESTING MILK. 141 

While many cows give milk below these standards 
(36), if found in the possession of an innocent dealer it is 
likely to be condemned as watered. It should be borne 
in mind that a great deal of milk that contains over three 
per cent of fat will not contain nine per cent solids not 
fat. This will be quickly seen if the percentage of fat is 
subtracted from percentages of total solids in analyses 
given in paragraph 38. 

80. The complete analysis of milk is a complicated 
process and not adapted for general use. The methods 
of analysis adopted by the Association of Official Agri- 
cultural Chemists are generally used at the United States 
Agricultural Experiment Stations. It is well to follow 
these methods, as they represent the combined experience 
of the best chemists of America, and are modified when- 
ever any improvements are worked out. They are pub- 
lished by the United States Government, and a copy can 
be had by sending five cents in coin to the Secretary of 
Agriculture, Washington, D. C. 

Full description of methods used by Babcock, Russell, 
and Vivian in detection and separation of the natural 
enzymes of milk, and in the separations and estimation of 
the nitrogenous compounds of milk other than casein, 
will be found in the fourteenth, fifteenth, and sixteenth 
annual reports of the Wisconsin Agricultural Experiment 
Station. An account of the salts of casein and paracase- 
in discovered by Van Slyke and Hart, and their methods 
of estimating the proteolytic compounds in milk will be 
found in the Tenth Annual Report, 1903, of the New 
York Agricultural Experiment Station (Geneva).* 

*The chemistry of casein of cows' milk is not yet well settled. The 
gross phenomena are well understood, but whether some of the compounds 
of casein with acids are physical or chemical, or both, cannot he definitely 

staled. 



142 INFANT FEEDING. 

English methods of analysis will be found described in 
"Richmond's Dairy Chemistry" (Philadelphia, 1899). 

It is interesting and instructive qualitatively to sepa- 
rate the proteids of cow's milk and breast milk for com- 
parison. The following working directions are very satis- 
factory for this purpose : 

Cow's Milk. 

Dilute 10 c.c. of fresh cow's milk with 90 c.c. tepid 
water. Add about 1.5 c.c. of 10 per cent acetic acid and 
stir until a coarse precipitate forms. Allow to settle 
until supernatant liquid is clear. Filter. The precipi- 
tate consists of casein and the fat of the milk. 

Boil the nitrate until a flocculent precipitate forms. 
This is albumin of milk. Filter. 

To the filtrate from the albumin add as much common 
salt as will dissolve. Then add 12 per cent aqueous solu- 
tion of tannic acid until no further precipitation occurs. 
The precipitate consists of albumoses and peptones. 

Breast Milk. 

Dilute 10 c.c. of breast milk with 40 c.c. of tepid 
water, stir, and cautiously add 10 per cent acetic acid 
until signs of precipitation appear. Then allow to stand 
until precipitate settles. Then filter and proceed as with 
cow's milk for albumin, albumoses, and peptones. 

There is a great difference between the behavior of 
cow's milk and breast milk with 10 per cent acetic acid. 
It will be nearly impossible to filter the casein from the 
breast milk and it may be necessary to boil the mixture 
before it can be filtered to determine the albumoses and 
peptone. In this case the albumin will be with the casein 
in the precipitate. 

81. Acidity of Milk is never determined directly, but 



METHODS OF TESTING MILK. 



143 



by the addition of some alkaline solution, the neutral 
point being determined by a color indicator, phenophtha- 
lein being generally used for this purpose. Milk fresh 
from the cow is quite acid to phenolphthalein, but almost 
neutral to litmus. Heating fresh milk, which drives off 
the gases it contains and possibly precipitates the acid 
salts of calcium, reduces the acidity greatly, as the follow- 
ing figures of Smethan and Ash worth quoted by Rich- 
mond show: 

Milk direct from the cow 26. 7° acidity. 

Milk direct from the cow, after boiling 12. 2° " 

Richmond recommends calculating as lactic acid the 
acidity to litmus, and gives as a reason the results from 
sour milk as follows : 





I. 


II. 


III. 


IV. 


V. 


Acidity (to phenolphthalein) .... 


1.24 

.65 


1.89 
1. 14 


1.82 
1.28 


1.52 
.86 


1.32 
.56 







82. For testing the acidity of milk decinormal alkali 
solutions are generally used, but as it is a delicate opera- 
tion to make these, and as they deteriorate on standing, 
Storch and also Richmond recommend the use of lime- 
water, which is almost exactly one-twentieth normal and 
which does not deteriorate if kept for any length of time, 
provided some lime is left in the bottom of the bottle. 
As the bottle becomes empty, all that is necessary is to 
add more distilled or rain water. 

Lime-Water. — Get from any grocery store an ounce 
or so of lime ; add a pint of water, and stir thoroughly. 
Allow the undissolved lime to settle, and pour off the 
clear lime-water, which will contain any potassium or so- 
dium that may have been present in the lime. Do this 
several times. Now pour on a quantity of distilled water, 



'44 



INFANT FEEDING. 



depending on the sized bottle the lime-water is kept in, 
and cork; when the lime has settled so the water is clear, 
it is ready to be used and may be removed as wanted with 
a pipette, as will be described presently. Always have 
some undissolved lime at the bottom of the jar, as by this 
means the lime water is readily kept saturated. As fast 
as the lime water is used, add distilled water to take its 
place. It is well to use a fresh lump of lime every two or 
three months, as in time the sediment may consist of 
carbonate of lime, owing to absorption of carbonic acid 
from the air. 

An easy way to test the acidity of milk is: (i) First mix 
the milk thoroughly, and (2) with a graduated 1 c.c. pi- 
pette, such as is used in measuring urine, or Fehling's 
sugar-test solution, place 1 c.c. of the milk in a small evap- 
orating dish or test-tube. (3) To this add one drop of an 
alcoholic solution of phenolphthalein (1 gm. to 30 c.c. 
alcohol). (4) With another 1 c.c. pipette add drop by 
drop clear lime-water, and shake the tube to mix thor- 
oughly, until the milk is colored a faint pink. Now note 
how many .1 c.c. of lime-water were used. 



1 c.c. mill 


c and 


Dhenolpr 


thalein color 


ed by o. i c.c. 

.2 " 

.3 " 

.4 " 

.5 " 

.6 " 

.7 " 

.8 " 

.9 " 

" 1.0 " 

" 1.1 " 

1.2 " 

" 1.3 " 

" 1.4 " 

" 1.5 " 


lime'water 


.045 
■99 

• 135 
.180 
.225 
.270 

• 315 
.360 
.405 

• 45o 

• 495 
.540 
.535 
.630 
.675 



METHODS OF TESTING MILK. 145 

A simple rule is: Multiply 0.0045, the weight in grams 
of lactic acid neutralized by 1 c.c. lime-water, by the num- 
ber of cubic centimetres of lime-water used, and divide 
by 100, which gives the percentage of acidity. 

Farrington has devised an alkaline tablet for use in 
testing acidity of milk. One of these tablets, which also 
contains phenolphthalein, is to be dissolved in one ounce 
or 30 c.c. of distilled or rain water. If one volume of milk 
is faintly colored pink by an equal volume of this solution, 
it contains 1.1 per cent acid; colored by 2 volumes, 0.2 
per cent acidity, and so on. These tablets, which are 
carried by many dairy supply houses, have recently been 
put up for use of physicians and families under the name 
of " ideal milk testers." Many of the wholesale druggists 
have them. 

It should be remembered that these methods of deter- 
mining acidity are only relatively correct. No exact 
method has been devised. Degrees of acidity, a term 
used in England, means the number of cubic centimetres 
of deci normal alkali needed to neutralize 100 c.c. of milk. 
Each degree corresponds to 0.009 P er cen t lactic acid. 

It has been widely taught that breast milk is alkaline 
and that the addition of five per cent of lime water would 
render cow's milk alkaline. Kerley, Gieschen, and Myers 
made some comparative examinations of breast milk and 
cow's milk at the New York Infant Asylum, and found 
that not a single specimen of cow's milk took less than 55 
per cent of lime water to render it alkaline, while "certi- 
fied milk" and "laboratory milk" required from 70 per 
cent to 85 per cent of lime water to render them alkaline to 

phenolphthalein. They also found that it was necessary to 

10 



146 INFANT FEEDING 

add 8 per cent to 24 per cent of lime water to breast milk 
to render it alkaline to phenolphthalein. In their exam- 
inations of milk, litmus paper was also used, and it was 
found that it was unreliable for testing milk, as one speci- 
men of the paper would show breast milk to be alkaline, 
while another specimen would show the same milk to be 
neutral. Richmond states that the use of litmus paper 
has been abandoned in scientific examinations of milk. 
A large number of examinations of the "certified milk" 
used for infant feeding at the New York Post Graduate 
Hospital have been made, and this milk required from 70 
per cent to 90 per cent of lime water to render it alkaline, 
although a few times it required but 50 per cent. It is 
found that the milk becomes thicker and more viscid in 
proportion to the amount of lime water required to render 
it alkaline, so there can be little doubt that some of the 
acidity of milk is due to the mucin of the milk, which is a 
weak acid that swells up after combining with the alkali. 

83. Preservatives in milk are not uncommon, espe- 
cially in summer, in country towns and small cities where 
milk is not inspected, and even in large cities some of the 
milk is not free from them. In another place (63) the 
composition of the principal preservatives now on the 
market is given, but as new preparations are likely to ap- 
pear from time to time no detailed method of detecting 
each will be given, but one broad method that will cover 
them all; viz., place a few cubic centimetres of milk in a 
test-tube, plug with cotton, and keep it at a temperature 
about 8o° to 90 F. This may be done by setting the 
tube in a cup of tepid water. If the milk does not sour 
or otherwise change in twenty-four hours, either the addi- 



METHODS OF TESTING MILK. 147 

tion of preservatives or pasteurization should be sus- 
pected. Formaldehyde can readily be detected in mak- 
ing the Babcock milk test (75), or by mixing equal parts 
of milk and water in a test-tube and adding, so as to not 
mix, a little concentrated sulphuric acid. A violet ring at 
the junction of the acid and milk indicates formaldehyde. 
C. P. sulphuric acid will not answer unless a minute 
quantity of ferric chloride is added. 

84. Sterilized Milk may be detected by first adding 
a starch and iodide-of-potassium solution, and then a drop 
or two of dilute peroxide of hydrogen. Milk heated 
above 175 F. remains unchanged; fresh milk or milk 
not heated to 175 F. is colored blue. This is Storch's 
test. 

To make the test: Add 1 mgm. cornstarch to 200 c.c. 
water, and boil. Now add 5 mgm. potassium iodide and 
filter after the flocculent matter has settled. 

To a mixture of one part of milk and two parts of the 
starch-iodide potassium solution, add one or two drops of 
a dilute (1 : 10) solution of peroxide of hydrogen. This 
test should be performed with fresh milk to get an idea of 
how it acts, before testing heated milk. 

85. Preservation of Samples of Milk. — It is some- 
times inconvenient to test a sample of milk for several 
days after it is obtained, or it may be necessary to send 
the sample away by mail or otherwise. In such cases 
add a few drops of formaldehyde and fill the bottle up to 
the cork, which should be tied in. If the bottle is not full 
the milk will churn and butter will form. 



CHAPTER XV. 

BACTERIOLOGICAL EXAMINATION OF MILK.* 

In order that a bacteriological examination of milk 
may be made which shall have any significance as indi- 
cating the wholesomeness or unwholesomeness of milk, it 
is necessary to know at the outset as much as possible in 
regard to the relation of various milk bacteria to health. 
Upon this subject unfortunately we are as yet in consid- 
erable ignorance. The few facts which we know may be 
briefly summarized. 

Diseases Attributed to Milk. 

It is certain that some well-known diseases are occa- 
sionally distributed by milk. 

86. Tuberculosis. — This disease is much more com- 
mon in childhood than was believed a few years ago. It 
is a well-known fact that cows suffer quite largely from 
tuberculosis, and that the milk which such cows produce 
is sometimes contaminated with tubercle bacilli. It is 
generally believed that such milk, if used as a food by 
infants, may give rise to tuberculosis in the child. There 
is, however, at the present time a considerable difference 
of opinion as to the extent of the danger to the child 
from this source. Whereas some are quite convinced 

* This chapter has been prepared by Prof. H. W. Conn, of Wesleyan 
University. 



BACTERIOLOGICAL EXAMINATION OF MILK. 149 

that the danger is very great and that a considerable por- 
tion of the infantile tuberculosis is attributable to milk, 
there are others that regard the danger as not very great. 
There seems to be sufficient evidence to prove that the 
child may acquire tuberculosis from this source, although 
we do not have, at present, sufficient evidence to indicate 
how great the danger may be. It is well to remember, 
however, that the tubercle bacillus does not multiply in 
the milk, and if the milk from one tuberculous cow is 
mixed with milk from a number of other healthy animals, 
the final product which is given to the child as food is 
quite likely to be diluted to such an extent that the tu- 
bercle bacilli, even though dangerous, are not present in 
sufficient numbers to produce much trouble. 

87. Typhoid Fever. — Perhaps typhoid fever is the 
disease that has been most frequently distributed by milk. 
It is at all events the one in regard to which we have the 
greatest amount of evidence. The number of typhoid 
epidemics that have been positively traced to milk is now 
very great. There are scores of instances where a com- 
munity suffers from an epidemic of typhoid of a more or 
less serious character, and where practically every case of 
the disease may be traced to milk from a certain source. 
An outbreak of a typhoid-fever epidemic in any commu- 
nity renders the milk suspicious, and the milk is the first 
point for investigation. The cow herself does not suffer 
from typhoid fever, and the typhoid bacilli which get into 
the milk must come from a different source subsequent 
to the time when the milk is drawn from the cow. This 
may be from a milker, who is recovering from or coming 
down with typhoid fever; it may be from the water of a 



150 INFANT FEEDING. 

well which has become contaminated with typhoid de- 
jecta, or it may be some other secondary source. As a 
rule, however, it is believed that the contamination is 
either from a typhoid patient, or some one who has in 
some way come in contact with a typhoid patient, or with 
typhoid contaminated water. Unlike the tubercle bacil- 
lus, the typhoid bacillus is capable of multiplying rapidly 
in milk. The result is that milk contaminated with ty- 
phoid bacilli is far more dangerous than milk contami- 
nated with tubercle bacilli. A few organisms that find 
entrance at the outset have an opportunity of developing 
rapidly before the milk is consumed, and the consumer 
swallows milk that contains typhoid bacteria in perhaps 
very large numbers. The result is that the danger of 
typhoid from typhoid-contaminated milk is very great, 
and the typhoid epidemics from such a source are apt to 
be violent. It rarely does any immediate good to trace a 
typhoid epidemic to milk from a given source. The milk 
is contaminated usually only for a day or two, and by the 
time the epidemic has appeared and it has been possible 
to trace it to milk from a given source, the contamination 
at that source has long since passed, so that nothing fur- 
ther can be done to check the development of the epi- 
demic in this direction. It is, of course, an advantage to 
introduce general sanitary precautions in the farm pro- 
ducing the milk, but no particular typhoid epidemic due 
to milk has been checked by the discovery of its 
source. 

88. Scarlet Fever and Diphtheria. — These two dis- 
eases are occasionally distributed by the milk supply, 
although our knowledge in regard to them is at present 



BACTERIOLOGICAL EXAMINATION OF MILK. 151 

somewhat fragmentary. We do not positively know 
whether the cows themselves suffer from these diseases 
in such a way as to contaminate their milk with the bac- 
teria in question. We do know, however, that milk may 
become contaminated with the infectious material of 
both of these diseases subsequent to the milking, and that 
sometimes such milk is the source of distribution of both 
of these diseases. The milk is, therefore, one of the fac- 
tors to be guarded against in the case of epidemics of 
diphtheria and scarlet fever, but beyond such simple facts 
our knowledge upon this matter is rather scanty. 

89, Diarrhceal Diseases. — In regard to the kind of 
bacteria which produce these difficulties, we are as yet in 
almost complete ignorance. There are quite a number of 
species of bacteria found in milk that have been demon- 
strated by bacteriologists to be capable of producing cer- 
tain poisonous secretions as the result of their growth. 
If these bacteria should grow in abundance in milk or in 
the intestine of the child, it is quite certain that they 
would produce toxic products, and such products would 
naturally produce intestinal disturbances. It is also a 
fact that the intestinal contents of children suffering from 
such troubles show a variety of fermentative changes, a 
putrefaction of some sort being extremely common. It is 
therefore probable that it is some of the micro-organisms 
which produce putrefaction that are responsible, in con- 
siderable degree, for these intestinal troubles. But 
beyond some such general suggestions as these, our bac- 
teriologists as yet are unable to make any very definite 
statements concerning the relation of bacteria to infan- 
tile intestinal disease. 



152 INFANT FEEDING. 

Value of Bacterial Examination of Milk. 

90. Recognizing these facts, the question arises as to 
whether a bacteriological examination of milk for the 
purpose of determining its healthful qualities is possible 
and practicable. A bacteriological examination of drink- 
ing-water has proved extremely useful as a means of as- 
sisting in determination of the healthfulness of drinking- 
water, although not in itself wholly satisfactory. It was 
quite natural that the methods of bacteriological examina- 
tion which were first used in the study of water should be 
transferred directly to the study of milk. The examina- 
tion of water has consisted in the past chiefly in deter- 
mining the number of bacteria that are present in a cubic 
centimetre of water, and drawing a conclusion as to the 
suspicious nature of the water from the number of bacte- 
ria that are present in a cubic centimetre of water. In 
more recent years there has been a further attempt 
slightly to differentiate the species of bacteria that are 
found. This method of quantitative bacteriological anal- 
ysis has also been applied to milk as a means of suggest- 
ing conclusions as to the healthfulness of milk. But 
when the method is applied it is found quite unsatisfac- 
tory, because the results obtained are totally different 
from those obtained in the study of water. So unlike are 
these results that the two problems appear to be wholly 
unlike. 

In the first place, the number of bacteria found in 
milk is quite incomparable with that found in any sam- 
ples of water. Whereas a sample of water containing a 
few thousand bacteria per cubic centimetre is immedi- 



BACTERIOLOGICAL EXAMINATION OF MILK. 153 

ately regarded as suspicious, it is a certain fact that many 
a sample of milk which is perfectly wholesome contains 
bacteria by hundreds of thousands and possibly by mil- 
lions. A comparison of the number of bacteria in water 
and milk will show in water the presence of a few hun- 
dreds per cubic centimetre, and in milk the presence of 
many thousands, hundreds of thousands, or occasionally 
millions. Even when compared to sewage, from the 
standpoint of the number of bacteria, milk proves to be 
surprisingly bad. The milk that is supplied to our cities 
frequently contains more bacteria than is present in the 
city's sewage, artd in the case of unusually bad samples of 
milk the number of bacteria outnumbers that which is 
found in the worst sewage. 

Manifestly the interpretations of the numbers of bac- 
teria as found in milk and in water cannot be the same. 
It is certainly not to be inferred that milk is a more un- 
healthful product than sewage because it contains a larger 
number of bacteria. The use of sewage as drinking-water 
would be disastrous, but milk that contains many more 
bacteria is used constantly without appreciable injury. 
The determination of the number of bacteria does not de- 
termine the wholesomeness of milk, and the interpreta- 
tion of the results in the study of milk is quite different 
from their interpretation in the study of water. We can- 
not condemn a sample of milk upon the same bacterio- 
logical grounds as those which force us to condemn a 
sample of water. 

The presence of small numbers of bacteria does not 
necessarily mean that the milk is wholesome, for among 
the small number there may be pathogenic forms which 



154 INFANT FEEDING. 

are distinctly injurious. On the other hand, the pres- 
ence of large numbers does not mean that the milk is 
necessarily unwholesome, for, if this large number of bac- 
teria contains only harmless or useful forms, their pres- 
ence is not detrimental. What, then, is the value of a 
counting of the number of bacteria in milk? 

Bacteriologists have learned that the number of bacte- 
ria in any sample of milk is dependent upon two factors. 
First, care in the dairy. Second, the care in transporta- 
tion and in using cleanly vessels and low temperatures. 
Milk produced in a dirty barn will contain larger num- 
bers of bacteria than milk from a clean barn, and the 
same general fact is true in connection with the methods 
in transportation. Hence it is that the bacteria count 
will enable us to determine, with considerable degree of 
accuracy, the question of the cleanliness of the dairy from 
which the milk was originally derived, and the care which 
has been given the transportation of the milk. If it is 
found that milk contains bacteria in large numbers — sev- 
eral millions per cubic centimetre — by the time it is ready 
for distribution, the inference is drawn that it has been 
placed under conditions which should be condemned. 
Either the original dairy failed to pay proper attention to 
cleanliness, or those concerned in the transportation of 
the milk have been careless in their work. If, on the 
other hand, the milk is found to contain a small number 
of bacteria, the conclusions are that the conditions have 
been satisfactory. 

Now, while it is true that milk that contains a small 
number of bacteria may perhaps contain pathogenic bac- 
teria and thus be dangerous, nevertheless in the majority 



BACTERIOLOGICAL EXAMINATION OF MILK. 155 

of cases milk which has been so carefully handled that 
the number of bacteria has been kept low has not been 
brought into a condition where it is likely to be contami- 
nated with pathogenic germs. Only the dairyman who 
takes care to protect his milk will be able to keep the bac- 
teria reduced to low numbers, and such a dairyman is one 
also who will be quite sure to guard his milk from con- 
tamination by pathogenic bacteria. On the other hand, 
the presence of large numbers of bacteria suggests care- 
lessness, and indicates, therefore, that there is a greater 
opportunity for the entrance into the milk of mischievous 
bacteria. Hence it is that while the presence of large 
numbers of bacteria does not necessarily mean that the 
milk is unwholesome, it renders us suspicious of condi- 
tions at its source and of the methods adopted in its 
transportation. 

It is difficult, perhaps impossible, to fix upon any 
standard as to the number of bacteria which wholesome 
milk may contain. Should we condemn milk when it 
contains ten thousand, thirty thousand, one hundred 
thousand, or a million bacteria per cubic centimetre? 
The question cannot be answered, because the answer 
will depend upon conditions and, to a large extent, upon 
the season of the year. It is at present impracticable to 
insist upon any definite standard at any season of the 
year for the general milk supply. It is true that in some 
cities a bacteriological standard has been set for a certain 
class of milk. Sometimes this standard has been set at 
ten thousand per cubic centimetre, sometimes at thirty 
thousand per cubic centimetre. Such standards are prac- 
tical only for special cases, and have been used only when 



156 INFANT FEEDING. 

some special dairy or milk dealer wishes to furnish a spe- 
cial product and receive an advanced price for the same. 
It is useful for the general plan of producing "certified 
milk," mentioned elsewhere in this work. But for the 
general supply of a large city, no standard can be insisted 
upon at the present time, without excluding most of the 
milk in the summer season. 

From all these facts it will follow that before a bacteri- 
ological examination of market milk can be satisfactory, 
it must be possible to do something more than determine 
simply the numbers of bacteria. Some method must be 
determined by which the different types of bacteria can 
be differentiated from each other, so that we may know 
how many of the suspicious organisms are present and 
how many are perfectly normal and probably wholesome. 
The question whether such a differentiation is possible 
has never been as yet thoroughly discussed, and hitherto 
no attempt has been made, in all of the bacteriological 
analyses of market milk, to separate the abnormal from 
the normal types, or to determine to what extent this im- 
mense number of micro-organisms may be perfectly 
wholesome and to what extent they are likely suspicious. 
Is such a differentiation possible? 

Differentiation of Types of Milk Bacteria. 

91. In the first place, we must notice that there is at 
present no practical possibility of detecting in milk the 
presence of the bacteria causing tuberculosis, scarlet and 
typhoid fevers, or diphtheria. The tubercle bacillus can 
be found in milk by proper tests, but the method is so 
difficult as to render it useless as a means of determining 



BACTERIOLOGICAL EXAMINATION OF MILK. 157 

the wholesomeness of milk. It has been hitherto quite 
impossible to detect typhoid bacilli in milk, and at pres- 
ent there seems to be no prospect of success in this line. 
The same is true in regard to the diphtheria bacillus, 
although the diphtheria bacillus may be detected in milk. 
The cause of scarlet fever is unknown, and there are thus 
no bacteriological methods as yet within our reach which 
enable us to detect in milk the bacteria which produce 
either of these four diseases. Inasmuch as we do not 
know positively the cause of the diarrhceal diseases, it is 
of course evident that bacteriological methods will not 
enable us to detect with any certainty whether the bacte- 
ria that produce them are present in milk or not. Hence 
it follows that bacteriological analysis of to-day will not 
enable us to detect satisfactorily the presence in milk of 
the exciting cause of any of the diseases most commonly 
distributed by milk. 

Nevertheless a partial differentiation of the milk bac- 
teria is quite feasible. To understand this it will be nec- 
essary to mention the chief types of bacteria which are 
found in normal milk, referring to their action upon milk 
and their probable relation to health. The number of 
species of bacteria present in milk is very great, and very 
little is known about the significance of most of them. 
We can, however, recognize among these bacteria three 
chief types which are readily distinguished from each 
other, and which probably have quite a different relation 
to the problems of the healthfulness of milk. 

92. (1) Lactic Bacteria. — These are the most common 
bacteria in milk which is a few hours old, although in 
freshly drawn milk they are frequently not very numer- 



I58 INFANT FEEDING. 

ous. There are several types of lactic bacteria, differing 
from each other in more or less important particulars. In 
milk in the United States there are three or four species 
which are particularly common and may be regarded as 
lactic bacteria par excellence. The chief of these, B. acidi 
lactici, is found widely distributed, not only in the differ- 
ent parts of the United States, but also in the countries 
of Europe. 

In their action upon milk these bacteria prove very 
troublesome, since they cause its souring and acid cur- 
dling (37). To keep the milk sweet it is therefore desir- 
able that their numbers should be kept as low as possible. 
As relates to their influence upon the wholesomeness of 
milk, however, it seems quite probable that they are not 
detrimental (52). Milk which does not contain lactic 
bacteria is liable to varied putrefactive fermentations, 
which are prevented by the development of the lactic-acid 
bacteria. Moreover, there are reasons for believing that 
their presence in the intestine is advantageous rather 
than detrimental. At all events there is no evidence to 
indicate that the normal lactic bacteria render the milk 
unwholesome. Milk with a moderate number of lactic 
bacteria is probably less liable to produce intestinal dis- 
turbances than milk which contains other types of bacte- 
ria and no lactic organisms. The presence of lactic bac- 
teria, therefore, will suggest a speedy souring of the milk, 
but will not give any suspicion as to its being unwhole- 
some as a food. 

93. (2) Bacteria Producing Albuminoid Decomposi- 
tion— The decomposition of albuminoid bodies fre- 
quently gives rise to putrefactive products. We know 



BACTERIOLOGICAL EXAMINATION OF MILK. 159 

nothing positive as yet as to the effect of such decomposi- 
tion products in our foods, although it is known that 
some of the products arising from such decomposition are 
toxic in nature. It would seem most probable that the 
products of albuminoid putrefaction will be unwholesome 
either in the food we eat, or in the milk we drink, or in the 
intestinal contents. Whether the intestinal disturbances 
which are common in warm weather are due to such bac- 
teria, and whether the summer troubles attributed to milk 
are traceable to such organisms, is not known. It is quite 
certain, however, that numerous putrefactive bacteria 
present in milk would render it at least suspicious. Milk 
containing many such bacteria will be more suspicious 
than milk with a much larger number of lactic bacteria. 
If it is possible by a bacteriological study of a sample of 
milk to detect the proportion of such putrefactive bacte- 
ria, it will give data which are of significance in the con- 
clusions as to the wholesomeness of milk. 

94. (3) Bacteria with No Noticeable Action on Milk. 
— These bacteria have apparently nothing to do with the 
keeping properties of the milk, and may be present in 
large numbers without producing any noticeable effect. 
Whether they are concerned in rendering the milk un- 
healthful cannot yet be stated. Probably some of them 
are, and if present in considerable numbers may render 
the milk unwholesome. Among these the most promi- 
nent is a variety of coccus forms, which belong to the ge- 
nus Streptococcus. These are almost universally present 
in milk. They come in part from the milk ducts (55), 
and it is almost impossible to draw milk without them. 
Their number is sometimes very great, and sometimes 



160 INFANT FEEDING. 

small. Their significance in determining the healthful- 
ness of milk cannot as yet be stated. 

95- It is possible by a simple modification of the 
common bacteriological methods of analysis to study milk 
in such a way as to differentiate these three types of bac- 
teria from each other. While such a differentiation will 
not, in the present state of our knowledge, be sufficient to 
determine accurately as to the wholesomeness of milk, it 
will bring us much closer to that end than the method of 
simply counting of numbers, and will frequently show 
whether, in the case of badly contaminated milk, the 
trouble is in the improper conditions of the original barn 
and in uncleanliness in milking, or due to improper hand- 
ling of milk subsequently to the milking. 

96. If milk is retained at a moderate temperature for 
quite a number of hours, the lactic bacteria commonly 
grow rapidly and soon come to outnumber all the other 
species put together. In fresh milk it is rare that the 
lactic bacteria are very numerous. Hence it follows that 
if a sample of market milk is examined and found to con- 
tain a large per cent of lactic bacteria of the common 
kind, it is due to the fact that the milk has been kept 
moderately warm for a number of hours. If the milk is 
kept cool the lactic bacteria do not thus grow, and re- 
main for a long time in small relative numbers. The 
presence of great numbers of lactic bacteria, therefore, 
suggests insufficient cooling of the milk and perhaps 
greater age. 

If, on the other hand, the milk shows large numbers of 
miscellaneous bacteria, either of the putrefactive type or 
of those having no effect on the milk, the inference to be 



BACTERIOLOGICAL EXAMINATION OF MILK. 161 

drawn is different. Under these conditions we are led to 
suspect a greater primary contamination of milk during 
the milking. If there is much filth in the barn and 
around the cow, the milk is likely to be contaminated 
with a large variety of bacteria. Hence milk which 
shows such variety suggests lack of proper conditions in 
the barn. Thus the relative abundance of lactic and 
other bacteria in a sample of milk may give data for con- 
cluding whether the milk w r as badly contaminated at the 
start, or whether it has simply been kept at too high a 
temperature so as to stimulate the growth of lactic bacte- 
ria. That there is a practical advantage in such a knowl- 
edge will be evident at once. 

Directions for Bacteriological Examination of 

Milk. 

97« In order to make a bacteriological study of milk it 
is necessary to have a previous knowledge of ordinary 
methods of laboratory work. It is assumed, therefore, 
that those who wish to use the following method have a 
previous knowledge of making and using culture media, 
and only such points will be explained in detail as contain 
modifications of the common laboratory methods. 

Culture Medium No. I. — Litmus sugar gelatin. 

I. Water 500 c.C. 

Peptone 10 gm. 

Milk sugar 30 " 

Gelatin 120 '' 

Liebig's extract of beef 5 " 

These materials are placed together in a dish and dis- 
solved by heating, at a temperature below 6o° C, to make 

a solution which, as will be seen, contains twice the quan- 
1 1 



162 INFANT FEEDING. 

tity of the various ingredients that is contained in the or- 
dinary gelatin culture media. After the material has be- 
come thoroughly dissolved the solution is neutralized. 
For neutralization is used a solution of NaOH, and the 
neutral point is determined by litmus paper. A weak 
solution of NaOH is added until the material is in the 
very faintest degree alkaline. In other words, since the 
solution is at first acid, just enough NaOH is added to 
pass the neutral point, as shown by its action upon red 
and blue litmus paper. After the neutralization the white 
of an egg is added and the whole is boiled for three-quar- 
ters of an hour. 

2. Water 500 c.c. 

Dry litmus (in cubes) 4S gm. 

The litmus is steeped in the water for three hours or 
more, at a temperature of about 6o c C, to dissolve as 
much of the active material as possible. The solution is 
then filtered. 

After solution i has boiled with the white of an egg 
for three-quarters of an hour, it is mixed with the filtered 
litmus solution No. 2, the two together making the bulk 
up to about a litre, and water is added if necessary to re- 
place evaporation. The solution is then warmed slightly, 
though not above 6o : , in order to avoid as much as possi- 
ble the changes in the litmus which high temperatures 
produce. It is then filtered through absorbent cotton, 
distributed in sterilized tubes, about 8 c.c. in each, and is 
ready for final sterilization. The sterilizing is carried on 
as usual by steaming on three successive days. The ster- 
ilization always has a tendency to change the color of the 
litmus to a reddish brown, but the blue is restored after 



BACTERIOLOGICAL EXAMINATION OF MILK. 163 

the litmus cools and stands for a few hours in contact 
with the air. When finally sterilized and cooled the so- 
lution should be a deep blue color, so deep a blue that 
when poured out in Petri dishes the color is quite strong. 
The litmus of commerce is quite variable in strength, 
three per cent of litmus (30 gm.) being sometimes suffi- 
cient to give the required blue color, while other lots of 
litmus require 40-50 gm. As a rule 48 gm. to the litre 
produces as good a color as can be desired, but some- 
times, if the litmus is exceptionally strong, a smaller 
amount is preferable. It is advantageous to buy the dry 
litmus in rather large quantities, and then after a single 
experiment has shown the amount of litmus of the partic- 
ular sample that is needed to produce the desired color, 
the same percentage of litmus is employed until the 
whole quantity of litmus has been used. A new sample 
of litmus will require a new percentage. 

Culture Medium No. 2. — Litmus Sugar Agar. — This 
medium is prepared in exactly the same way as was the 
gelatin culture medium, except that one and one-half per 
cent of agar is added instead of twelve per cent of gelatin. 
The other methods of procedure are the same. 

98. In the use of these media for the analysis of the 
milk, the first thing that is to be done is to determine 
upon the proper dilution of the milk which will give the 
most satisfactory results. Milk contains so many bacte- 
ria that is never possible to use as much as 1 c.c. of milk 
in a single test, as is commonly done in water testing. 
The milk must therefore be diluted with sterilized water. 
The question of determining the amount of dilution is 
one of the most difficult points connected with the whole 



1 64 INFANT FEEDING. 

testing, from the fact that different samples of milk re- 
quire different dilutions for proper study. The dilution 
should be such that the plates which are subsequently 
made should contain from one hundred to three hundred 
colonies of bacteria. The extent of the dilution of the 
milk necessary to produce this result varies with the age 
of the milk, with the temperature, and with the season. 
We have found in winter weather that a dilution from 
two hundred to six hundred times is ordinarily most satis- 
factory. In summer weather the dilution should be 
higher. From one thousand to five thousand dilutions 
are necessary if the milk is somewhat old or during warm 
weather. The determination of the proper dilution re- 
quires some degree of judgment and experience, and it is 
always best to use more than one dilution for each experi- 
ment, in order that the best results should be obtained. 

Method of Procedure. 

99- Sterilize a number of small flasks which are 
marked in some way (best by being etched) at the 99 c.c. 
point. Sterilize also a number of small vials, some of 
which are marked at the 5 c.c. point, and others at 19 c.c. 
These vials should be provided with corks, which are laid 
loosely in the mouth during sterilization, but placed in 
tightly after sterilization. Sterilize a litre or more of 
water in an autoclave under steam pressure in the ordi- 
nary manner. 

At the beginning of an experiment fill one of the 
flasks to the 99 c.c. point with sterilized water, and fill 
one of each sized vial to its mark in the same way. One 
cubic centimetre of the milk is taken from the milk to be 



BACTERIOLOGICAL EXAMINATION OF MILK. 165 

tested in a sterilized 1 c.c. pipette, and placed in the flask 
with the 99 c.c. of water; this dilutes it one hundred 
times. One cubic centimetre of this mixture is then 
placed in one of the vials, in the 5 c.c. vial if the dilution 
desired is to be six hundred, and in the 19 c.c. vial if the 
dilution is to be two thousand. 

Meantime a number of tubes of the litmus gelatin and 
one or two tubes of litmus agar have been melted. There 
is now taken from the flask containing the 100 c.c. milk 
dilution one-half of a cubic centimetre with a sterilized 
pipette, and this is mixed with one of the tubes of gelatin. 
This, after being thoroughly mixed in the gelatin by a 
gentle but thorough shaking, is poured into a Petri dish 
and allowed to harden. It is best to make at least three 
such inoculations, each containing one-half of a cubic cen- 
timetre of the liquid in the flask. These are then labelled 
as diluted two hundred times. To obtain the dilution of 
six hundred times, 1 c.c. of the mixture in the small vial 
is removed by a sterilized pipette, and as before mixed 
with the gelatin in the gelatin tubes and poured out into 
Petri dishes. At least three such plates should be pre- 
pared from this dilution, and these must be labelled as 
diluted six hundred times. If the higher dilution is re- 
quired, 1 c.c. of milk from the first flasks of 100 c.c. is to 
be put into the vial containing 19 c.c. of water. This 
will dilute the original milk two thousand times, and 1 c.c. 
of tins is mixed with a tube of gelatin and poured out in 
Petri dishes as usual and labelled as diluted two thousand 
times. To obtain a dilution of four thousand times, one- 
half a cubic centimetre from the vial is mixed with a tube 
of gelatin. 



1 66 INFANT FEEDING. 

From each sample of milk there should be made at 
least six plates, with two different dilutions. It is desira- 
ble also to make at the same time two plates with the 
agar culture medium, for reasons to be mentioned pres- 
ently. For this purpose i c.c. of the mixture diluted six 
hundred times is placed in a tube of agar culture medium 
No. 2, mixed thoroughly, and poured out in a Petri dish. 
There will thus be prepared for each experiment eight 
plates, three of which are made with a dilution of two 
hundred or two thousand in gelatin, and three in a dilu- 
tion of six hundred or four thousand in gelatin, and two 
in agar. These plates are then set aside at ordinary tem- 
perature to grow. 

Study of Plates. 

ioo. In the study of the plates it is always necessary 
to allow the plates to grow for three or four days if pos- 
sible. The reason for this is that not until the fourth day 
do the different colonies become so well developed as to 
be distinguishable from each other. The great difficulty 
of the whole method consists in the fact that it sometimes 
happens that the milk contains many liquefying bacteria 
which grow rapidly and liquefy the gelatin. If the gela- 
tin begins to liquefy rapidly it is necessary to study the 
plates at once in spite of the fact that the differentiation 
is not perfect. If, however, the liquefying bacteria are 
not numerous and do not grow rapidly, the plates may be 
kept for four or five or even more days before they are 
studied. The longer the plates grow the better the dif- 
ferentiation which is obtained. 

At best, however, the presence of liquefying bacteria 



BACTERIOLOGICAL EXAMINATION OF MILK. 167 

will make it impossible properly to differentiate the bac- 
teria in a considerable number of the samples of milk, 
and sometimes they are so numerous as to make it even 
impossible to determine the numbers of the colonies, to 
say nothing of determining the varieties. For this rea- 
son the two agar plates are introduced in the experiment ; 
the agar plates, not being liquefied, will serve as a test 
upon which we can fall back if the gelatin plates become 
ruined by the growth of liquefiers. The agar plate is not 
so satisfactory as the gelatin plate, and is to be used only 
when the gelatin plates prove unsatisfactory because of 
liquefiers. 

In the study of the colonies on the plates, after they 
have satisfactorily grown, several points are to be deter- 
mined : 

1 . The total number of bacteria. These are counted 
by the ordinary methods. 

2. The number of acid-producing bacteria. These 
can be easily detected from the fact that each acid colony 
will be surrounded by a little red halo where the acid col- 
ony has turned the blue litmus red. This detection of 
the acid bacteria is also possible on the agar. 

3. The number of liquefying colonies is to be counted. 
This is especially important, inasmuch as the liquefying 
colonies commonly represent the putrefactive organisms, 
and their relative abundance in milk is a matter of impor- 
tance. 

4. The number of bacteria producing no reaction in 
the gelatin or an alkaline reaction, and which do not 
liquefy, is to be counted. This is very easy to do, pro- 
vided the plates have been properly diluted and have 



[68 



INFANT FEEDING. 



grown sufficiently. Where it is necessary to study the 
plates early because of the abundance of liquefiers, the 
distinction between the acid bacteria and those producing 
no reaction is less sharp and not always satisfactory. 

The results which are obtained should then be tabu- 
lated, and each table should be a double one. First, 
there should be given the total number of each type of 
bacteria detected; and second, the percentage of each 
type. The purpose of the latter is to show the relative 
preponderance of the different micro-organisms. The 
advantage of this is considerable. It has been found by 
many experiments that usually, when milk becomes a 
number of hours old, the bacteria increase rapidly, but 
the large percentage of the numbers present are lactic 
bacteria. If the milk shows large numbers of bacteria, 
and of this large number the great proportion are lactic 
organisms, the milk must be regarded as normal, though 
rather old. If, on the other hand, the results should show 
large numbers and a large percentage of liquefiers, or a 
large percentage of the non-acid bacteria, the milk must 
be regarded as possibly more suspicious. Examples of 
the tests of two samples of milk in this manner will be 
given as follows in the way of illustration: 



No. i. 





Total. 


Lactic bacteria. 


Liquefiers. 


Miscellaneous. 


Number of bacteria per c.c. 


6,820,000 


6,324,000 
93 


68,000 

I 


428,000 
6 








No. 2. 


Number of bacteria per c.c. 


17,000 


500 

2.S 


5,300 
31 


1 1 , 200 
66.2 









BACTERIOLOGICAL EXAMINATION OF MILK. 169 

Of these two samples it will be seen that the first con- 
tains many more bacteria than the second, but the per- 
centage of lactic bacteria is much greater. The second 
sample contains small numbers, but with a very small per 
cent of lactic bacteria. The second sample of milk is 
doubtless fresh, but the first is a perfectly normal milk 
and not suspicious in spite of its large numbers. If No. 
1 with its high numbers had had large percentages in the 
third and fourth columns, it would have been suspicious. 

This method of testing milk is not given here as by 
any means complete, nor is it assumed that the results 
obtained will enable us to determine positively the whole- 
someness of milk. Such a method of bacteriological 
study is, however, an advance over the practice of simply 
counting the numbers, which has been the common 
method of the past. 



CHAPTER XVI. 



CEREALS AND VEGETABLE FOODS. 



Next to milk, cereals are the most important articles 
of diet, especially for older infants and young children. 
These all contain more or less fat, protein, carbohydrates 
(starch), and mineral matter; but these ingredients are 
stored up in cells composed of 
cellulose. Cotton fibre or paper 
is almost pure cellulose. While 
the herbivorous animals can di- 
gest large quantities of this 
cellulose, as their digestive tracts 
are specially adapted for this 
purpose (6), human beings can- 
not digest it except to a very 
limited extent. To enable the 
human digestive juice to get at 
the nutritious portions, vegetable foods must be cooked, 
which process ruptures the cells and allows the digestive 
juices to enter and dissolve their contents. 

101. The protein of plants assumes many forms, the 
same as in animal tissues. Instead of multiplying the 
weight of nitrogen of cereals by 6.25, as has been usually 
done in determining the weight of protein, new factors 
are being used, as will appear farther on. 




Fig. 43-— Showing Cells Containinj 
Finely Divided Protein Matter Inter 
mingled with Starch Grains. (Good 
ale.) 



CEREALS AND VEGETABLE FOODS. 



171 



The proteids of wheat flour (N X 5.70) are composed 
of*: 

Per cent. 
Albumin, o. 3 — soluble in water ; coagulable by heat. 



Globulin, 
Proteose body, 
Gliadin, 6 

Glutein, 4 



9 " dilute salt solution ; coagulable by heat. 

2 " water. 

8 " dilute alcohol. 

5 — insoluble in water, salt solution, and dilute alcohol. 



The proteids of barley (N X 5.68) consist of*: 

iLeucosin o. 30 per cent. 

Hordein 4. 00 " 

Edestin proteose 1.95 " 

Insoluble proteid 4. 50 " 



Oats are said to contain three principal forms of pro- 
teid, making a total of about fourteen per cent. Their 
weight is determined by N X 6.10. 

102. When most vegetable substances are boiled with 
water, the heat and moisture combined cause the contents 





Fig. 44.— Wheat Grain Showing Cells Cc 
taining Starch Granules. (Goodale.) 



Fig. 45.— Barley Grain, a. Chaff ; <5, adherent 
cellular layer ; </, starch granules. (Goodale.) 



of the cells, particularly the starch grains, to swell up and 
break open the cells. 

The rapidity with which this process takes place de- 
pends largely on the nature of the substance to be cooked 

*Bull. 13, Part 9, Div. Chemistry, United States Dept. Agriculture. 



i ; 2 INFANT FEEDING. 

and its physical condition. Potatoes, being very watery, 
swell up and burst as soon as the temperature reaches 
near the boiling point of water. 

Whole cereals are hard and dry and have an outer 
coat that is almost waterproof, and even when placed in 
water it is some time before the cereals soften. If the 
whole cereals are brought to a boil, the starch in the 
outer cells swell up and the proteid coagulates, thus form- 
ing a coating which protects the interior of the grains 
from moisture. It takes many hours of boiling to disin- 
tegrate such cereals; but, if the 
cereals are first ground in a mill, to 
rupture the cells, and then boiled in 
water, the swelling up and bursting 
of the starch grains takes place in 
a few minutes. 

There are a great many so- 
called " steam cooked " cereal break- 
f,g. 46. -oat Grain. * starch fast foods on the market, which 

granules. (Goodale.) J^^ J^^ p^alty g r0U nd, that it 

is claimed require but a few minutes' cooking, but many 
of them will bear an hour's boiling with great advantage 
to the user. When they are thoroughly cooked, all trace 
of the original grain should have disappeared, or they 
should at least be very soft. 

A general idea of the composition of such foods may 
be had from the following analyses of some of those best 
known. It will be noticed that there is very little differ- 
ence between any of them of the same class. The claim 
that some of these foods are equivalent to ten times their 
weight of meat, wheat, oats, or other such food, should 




CEREALS AND VEGETABLE FOODS. 



173 



not be believed, and the use of foods for which such ex- 
travagant claims are made should be discouraged. As a 
rule, these foods are very well digested and absorbed if 
properly prepared. 



Corn Products. 

Pearl Hominy * 

Pearl Samp * 

Oat Products. 

Hornby's steam cooked oat- 
meal * 

Quaker Oats * 

Wheat Products. 

Cream of Wheat f 



Germea ' 



Pettijohn's Breakfast Food f 

Pillsbury's Vitos \ 

Shredded Whole Wheat Bis- 
cuit f 



Wheatena • 



Wheatlet* 

Miscellaneous. 

Cook's Flaked Rice f 



Grape Nuts \ 

Malt Breakfast Food f . 
Whole Wheat Gluten f. 



Health Food Co.'s Cooked 

Gluten * 

Kingsford Oswego Corn 

Starch * 

Durkee's Pearl Tapioca*. . . 

Johnson's Gluten Flour No. 6$ 

Johnson's Washed Oluten No. 

It 



<D* 






3 


Proteid. 


wS^ 


§ 








NX 6.25 




13.05 


8.31 


O.60 


"•43 


8.25 

NX 6.31 


.81 


8.q2 


16.22 


6.89 


7.86 


16.22 

N X? 


8.23 


I2.00 


S.io 
NX 5-70 


.90 


IO.28 


7.98 
NX ? 


1.88 


IO.70 


11.90 


1. So 


9-30 


11. 19 


1.50 


IO.80 


10.60 

NX 5.70 


i-5o 


9.65 


12.26 
NX 5.70 


3-45 


II.78 


10.38 
NX? 


1. 5i 


II.40 


7.90 
NX? 


1. 00 


5-30 


11.70 
N X? 


1. 10 


S.OO 


13.40 
NX? 


2.20 


II.20 


15.90 
NX 6.25 


4.60 


6.81 


12.75 
N X 6.25 


• 71 


II.65 


• 44 




II.46 


.38 


.09 


9-43 


33-44 


2.00 


7.62 


75-44 


1-33 



Carbohydrates 
other than fibre 



77.62 
79-26 



66.16 
66.07 

Carbohydrates. 

78.70 

Carbohydrates 

not fibre. 

78.68 

Carbohydrates. 

73-90 

76.60 



75.60 



Carbohydrates 
not fibre. 



75-21 

Carbohydrates. 
80.20 

79-70 

75-00 

65.60 

Carbohydrates 

not fibre. 

79.96 

S7.48 
87.95 
49.22 



7.8l 



O.63 
I.03 



I. II 

1-25 



1.39 
I.08 



.85 

•23 
.09 
I. 17 

0.75 



O.42 

•25 



I.S2 
1.62 



I.70 

.70 

I.50 

1-54 
1. 12 
O.4O 
2.30 
I.40 
2.70 

1. 01 

•43 

.12 

0.51 

0.5S 



*Bull. No. 13, Part 9, Div. of Chemistry, 1 nited States Dept. Agriculture. 

f Bull. No. 55, Maine Agricultural Experiment Station. 
JNew Hampshire Sanitary Bulletin, October, 1903. 



174 



INFANT FEEDING. 



Dried beans and peas are very rich in protein, but as 
usually cooked, forty to forty-seven per cent of this is 
unabsorbed, and the toughness of the cellulose renders 
them unsuitable for a steady diet. However, when made 
into soup, beans and peas may be used quite freely with 
advantage after infancy. 



Composition. 


Water. 


Protein. 


Fat. 


Carbo- 
hydrates. 


Ash. 


Authority. 


Dried lima beans 


IO.4 
9-5 


1S.1 
24.6 


1-5 
1.0 


65-9 
62.O 


4.1 

2.9 


At water. 







103. Long before children are old enough to eat these 
familiar foods, cereals can be and should be used when 
properly prepared and given with discretion. In the sec- 
tion on " Practical Infant Feeding" (133) the methods of 
using cereals will be found, but a rather detailed account 
of the principles involved in preparing them will be given 
here. 

Cereals are composed principally of stored-up food for 
the plant germs which they contain. These germs have 




Fig. 47.— Showing Bursting of Starch Grains during Cooking. (Langworthy.) 

the power to secrete enzymes (n), which dissolve nearly 
all of this reserve food, that nourishes the little plant 
until its roots have obtained a hold in the ground and its 
leaves are above the soil. The enzymes produce for the 



CEREALS AND VEGETABLE FOODS. 



i75 



plant germ, as nearly as is known, the same changes in 
the starch and protein of the cereals as do the digestive 
juices of human beings. These enzymes, or diastases, 
have different properties ; some will simply dissolve the 
cellulose, others will liquefy the starches, and still others 
convert them into dextrin and maltose. The enzymes 
that dissolve the proteids of cereals are not of great im- 
portance in preparing cereals for infants. 

By taking advantage of this knowledge (1) cereals can 
be rendered almost perfectly assimilable by the youngest 
infant with little or no di- 
gestive effort on its part ; 
(2) or the starch of the 
cereal may be simply ren- 
dered soluble (137). This 
is the principle on which 
Baron Liebig prepared his 
infant food. 

104. Another process 
of converting starch into 
dextrin and maltose con- 
sists of heating it uniform- 
ly to about 400 F. The 
starch grains do not lose 
their shape, but become soluble and lose their chemical 
properties. An old process of preparing wheat flour for 
infants and invalids consists in placing several pounds of 
flour in a cloth bag, and this in a kettle of boiling water 
and boiling for several hours. The bag is then removed 
and the doughy coating of the mass removed and a " flour 
ball " remains. A much simpler method is to put the flour 
in a " tin pudding bag," or rice mould, and boil for an hour. 




Tin Pudding-Bag or Rice Mould. 



76 



INFANT FEEDING. 



The tube in the centre of the tin enables the flour to be- 
come heated quite rapidly, and if the kettle in which the 
boiling is done is kept covered the temperature of the flour 
will rise to above 200 3 F., but not quite to 21 2° F. This 
"baked flour" has a slightly yellow color and it is often 
said to be " dextrinized," or that the starch in it has been 
converted into dextrin. As a matter of fact, none or very 
little of the starch is converted into dextrin, as this process 
does not take place until the heat is raised to about 400 F. 
The change in this "baked flour" or "flour ball " lies in 
the coagulation of the proteids. If the baked flour is 

mixed with cold water, it 
will not form a dough 
or even lumps, but will 
settle out like raw starch. 
When mixed with water 
and boiled, there is no 
soluble proteid to coag- 
ulate around the starch 
grains and prevent their 
swelling up and bursting. 
In this point "baked 
flour " has a slight advan- 
tage over raw flour, but it 
is not so digestible as raw flour unless made into gruels, 
as will be explained in the next paragraph. 

105. From the foregoing it might be inferred that 
there is no advantage in baking bread or crackers as far 
as change of the starch goes, but this is an error. Y\ Tien 
flour is mixed with tepid water, there commences to be a 
conversion of starch into sugar that is caused by enzymes 




Fig. 49— Appearance of Starch Grains in Bread 
from Flour Ground in Dreef's Mill; magnified no 
diameters (Reduced one-third; Bull. No. 67, 
U. S. D. A. Office, Exper. Sta.) 









CEREALS AND VEGETABLE FOODS. 177 

natural to the flour, but which are destroyed in the baking 
process. During the process of making bread about six 
per cent of the starch is converted into sugar by these 
enzymes. The object of adding yeast to bread dough is 
to cause the formation of gas, which, as it expands, ren- 
ders the gluten in which the starch grains are embedded 
porous and spongy. The heat of baking coagulates the 
gluten and other coagulable proteids and drives off the 



Fig. 50.— Wheat Starch; magnified 160 diameters. (Bull. No. 13, Div. of Chem., U. S. D. A.) 

gas ; the result is a porous food which exposes an immense 

surface to the digestive juices. Few cereals contain as 

much gluten as wheat, and consequently are not so well 

adapted for bread-making. 

While the starch of baked flour is not in a condition 

to be easily digested, that of bread and crackers is readily 

digested. There are two reasons for this: (i) the action 

of the natural enzymes of the flour on the starch in the 

dough before baking, and (2) the effect of the heat on the 
12 



i;8 



INFANT FEEDING. 



wet starch in the dough, which causes the starch grains 
to break open. The crust of bread may contain a small 
quantity of dextrin produced by heat, but none is formed 
in the interior of the loaf, as there the temperature never 
exceeds 21 2° F. 

106. In selecting bread there is little or no advantage 
in choosing "whole-wheat bread" or Graham bread on 
account of their containing more mineral matter than 
ordinary bread, for digestion experiments have shown 
that owing to the greater quantity of cellulose in these 
breads absorption is not so complete as with white bread. 

Representative Analyses of Bread.* 





Water. 


Protein. 


Fat. 


Carbohydrates. 


Ash. 




36.06 
41.92 

33.34 


8.7S 
8.24 
9-43 


1.73 
I.05 
2.62 


52.73 
46.85 
48.21 


O.70 
I.94 
I.40 




Entire wheat bread 



Representative Analyses of Crackers and Biscuits. f 



Water. 


Proteids. 


Ether ext. 
(Fat.) 


Crude 

fibre. 


Ash. fe 


alt. 




NX 5.70 










5-42 


S.44 


S-37 


O.4S 


O.65 O 


04 


9.4S 


10.21 


8.79 


•27 


2.51 2 


25 


4.28 


9.01 


13-77 


.80 


1.33 


53 


5.24 


7.52 


12.04 


•59 


1. 18 


35 


3- M 


6.79 


10.87 




I.42 


29 


8.S7 


S.15 


12.47 


•37 


I- 15 


37 


6.72 


S.72 


3-54 


• 42 


.62 


08 


7.83 


11.97 


3-54 


1.86 


2-33 


05 


b.51 


10.21 


9.19 


.21 


3.07 2 


27 


8.18 


9-52 


10.22 


• 27 


.91 


40 


6.70 


10.21 


12.68 


• 34 


2.26 1 


74 


7-53 


9.07 


10.17 


•39 


1.44 


93 


8-43 


8.89 


7.6S 


•25 


2.04 1 


28 


6.58 


10.83 


.21 


.29 


•49 


02 


7-73 


9.40 


9.12 


•30 


•S3 


20 



Carbo- 
hydrates. 



Animal crackers . . . 
Butter crackers. . . . 
Cream crackers. . . . 
Graham crackers. . . 
Graham wafers .... 
Lunch milk biscuits 
Nursery biscuits. . . 

Oat cakes 

Oyster crackers .... 

Pilot biscuits 

Saltines 

Sea Foam wafers . . 

Soda crackers 

Water crackers 
Zwieback 



77.12 
69.01 
71-56 
74.02 
77.78 
69.36 
80.40 
69.33 
71.02 
71.17 
68.86 
71-79 
72.96 
81.89 
72.92 



* Bull. No. 85, United States Dept. of Agric, office of Exper. Stations. 
+ Bull. No. 13, Part 9, United States Dept. Agric, Div. of Chemistry. 



CHAPTER XVII. 
PROPRIETARY INFANT FOODS. 

These foods are largely made from wheat flour, to 
which may have been added a small quantity of milk, 
beef extract, or sugar. 

In the foods that are to be dissolved in water the 
starch has been converted into dextrin and maltose by 
the action of diastase, the starch-digesting enzyme of 
plants (103) ; and in the foods that are to be cooked, the 
flour has been baked, as can be done at home by the use 
of the "tin pudding bag" (104), hence the principles used 
in theii manufacture are the same as those explained in the 
previous chapter. 

From a nutritional standpoint these foods by them- 
selves are almost without exception inferior to the best 
grades of condensed milk. When used with cow's milk, 
however, many of them are effective diluents, especially 
those containing baked flour. Incases of indigestion they 
sometimes prove helpful, but as a steady diet for an in- 
fant they should not be used unless along with a liberal 
amount of fresh milk. 

Analyses of those foods that are said to have the larg- 
est sale are here given, with analyses of condensed whole 
and skim milk, and wheat flour. It will be noticed that 
many of the foods contain not much more fat than con- 
densed skim milk. Fat is a very important food element 



180 INFANT FEEDING. 

when derived from milk, as it then contains lecithin, one 
of the nerve-building elements. Whenever it is possible, 
an infant should have a sufficient quantity of fat from 
fresh milk. 





Moist- 
ure. 


Fat. 


Pro- 
teids. 


Carbo- 
hydrates. 


Ash. 


Crude 
fibre. 


Condensed whole milk (sweetened) 


24.06 
29.23 

12. 28 


11.28 

.64 
Ether 
ext. 
I.30 


9-36 
I0.73 

IO.lS 


52.28 
55-69 

75-63 


2. 13 
2.63 

.61 




Wheat flour f 


O.28 







Proprietary Infant Foods which have Principal 
Sale in New York. 

Class I. To be used with water; no cooking re- 
quired. 

Allenbury's Foods Nos. 1 and 2. Cereal Milk, Malted 
Milk, Milkine. These foods are said to be prepared by 
mixing a certain amount of sugar, or dextrin and maltose, 
derived from the starch of wheat flour with milk and dry- 
ing. 

Analyses to represent this class \% 



Allenbury's Food No. I § 
Allenbury's Food No. 2 § 

Malted Milk || 



Moist- 
ure. 



5-7 
3-9 



14.00 
12.30 



N X 5-7 

9 7 

9.2 

N X 6.25 

14.00 



Soluble 
carbo- 
hydrates. 



66.85 
72.10 



63.87 



Insoluble 

carbo- 
hydrates. 



15-68 



3-75 
3- 5o 



3-57 



* Richmond's " Dairy Chemistry." 

f Bull. 13, Part 9, Div. of Chemistry, U. S. Department Agriculture. 

% See first note on page 173. 

§ Hutchinson : " Food and the Principles of Dietetics." 

I Bull. 59, Laboratory of the Inland Revenue Department, Canada. 



PROPRIETARY INFANT FOODS. 181 

Class II. To be used with water; cooking required. 
These foods are said to be prepared by adding to some 
dried milk, sugar, and baked wheat flour. The cooking 
with water is to rupture the starch grains. 

Analysis to represent this class*: 

Nestle' s Milk FooD.f 



Moisture 2.18 

Fat 4.45 

Proteids 10. 72 



Soluble carbohydrates 43. 84 

Insoluble " (starch) 35. 34 
Ash 1.60 



Class III. To be used with milk; no cooking re- 
quired. 

These foods are said to be made from wheat flour by 
converting the starch into dextrin and maltose by dias- 
tatic action (103). 

Analysis to represent this class:* 

Mellin's FooD.f 



Moisture 4. 72 

Fat 30 

Proteids, NX 6. 25.... 10.10 



Soluble carbohydrates 82.06 

Insoluble carbohydrates 

Ash 3.50 



This food often gives good results by acting as an 
effective attenuant of the curd of cow's milk to which it is 
added. 

Class IV. To be used with milk; cooking required. 

Carnrick's Soluble Food, Eskay's Food, Health Food 
Company's Barley, Hubbel's Prepared Wheat, Imperial 
Granum, Ridge's Food, Robinson's Patent Barley. With 
the exception of Carnrick's Food these are said to be 
principally made up of baked wheat or barley flours. 

* It is impossible to give the composition of the food as it will be in the in- 
fant's feeding bottle, as this will depend on the dilution of the food and the quan. 
tity of milk that is added to it. 

f Bull. 59, Laboratory of the Inland Revenue Department, Canada. 



1 82 INFANT FEEDING. 

Analyses to represent this class*: 



Carnrick's soluble foodf 

Imperial Granum f 

Ridge's Food f 

Health Food Co. 's Barley \. . 
Robinson's Patent Barley f . . 



Moist- 
ure. 


Fat. 


Proteids. 


Soluble 
carbo- 
hydrates. 


Insoluble 

carbo- 
hydrates. 






NX 6.25 






5.69 


2.18 


16.60 
N X 6.25 


38.21 


34-54 


6.04 


.72 


13-77 
N X 6.25 


3-94 


67.46 


8.12 


.48 


13.83 
NX 5-82 


5-02 


69.24 


IO.92 


.89 


6.98 
N X 6.25 


? 


80.35 


9.41 


.41 


7.46 


2.9I 


78.66 



2.78 
.49 

53 
86 

04 



These foods often form effective, though expensive, 
diluents of ordinary cow's milk. 

* See first note on page 173. 

f Bull. 59, Laboratory of the Inland Revenue Department, Canada. 

X Bull. 13, Part 9, Div. of Chemistry, U. S. Department Agriculture. 



CHAPTER XVIII. 
MEATS AND EGGS. 

Scraped Beef — Beef Juice — Beef Extracts and Teas 
— Meat Broths and Soups — Eggs. 

107. Meats play but a small part in infant feeding, yet 
there is a great deal of misapprehension as to their value. 

It is impossible to give the composition of meat, as it 
varies greatly with the cut. However, in a general way it 
consists of: 

Water 50 to 75 per cent. 

Protein 15 to 20 " 

Fat 15 to 20 " 

Mineral matter 1 to 3 " 

The protein or proteid of meat is a mixture of several 
protein bodies, some soluble in water and salt solution 
and coagulable by heat (albumins and globulins), and oth- 
ers insoluble. A detailed account of these proteids will 
be found in Chapter III. About the only attempt to 
separate the proteids of meat in infant feeding is in 
preparing scraped beef, or beef pulp, and beef juice. 
Meat broths and soups contain the extractives of the 
meat, but only a small quantity of proteid. These prep- 
arations are all useful in cases of poor digestion, as will be 
explained presently. 

108. Scraped Beef or Beef Pulp. — If a piece of lean 



1 84 INFANT FEEDING. 

beef is scraped with a spoon, a finely divided pulpy mass 
will be obtained on the spoon and a stringy fibrous mass 
will remain, which consists of the connective material of 
the meat. Upon boiling, this fibrous matter is converted 
largely into gelatin, which gives the "body" to beef 
soups. 

The gastric juice has a particular solvent action on the 
fibrous matter of meat, and causes the meat in the stom- 
ach to swell up and disintegrate into a pulpy jelly, which 
can easily pass into the intestine where the principal chem- 
ical changes take place during digestion. As the intesti- 
nal juices do not cause meat to swell up and disintegrate, 
but attack the meat only on the outside surface, digestion 
is very slow in the intestine unless the gastric juice has 
first done its preparatory work (n, 151). 

In infants the stomach is not fully developed and 
consequently for them meats are very indigestible. How- 
ever, if the meat pulp is removed from the connective 
material, older infants can take care of it without difficulty, 
as it can easily pass into the intestine where the chemical 
processes have been established. Scraped beef has a 
highly nutritive value. 

109. Beef Juice. — By pressure a certain amount of 
juice can be obtained from lean beef, especially if the 
meat has been slightly broiled, which causes it to con- 
tract greatly. This juice is not blood, but muscle serum. 
Its solids consist principally of fat, albumins, and globu- 
lins, which coagulate upon heating, certain by-products 
of proteid metabolism, called extractives or meat bases, 
and salts. 

The proteids of this beef juice or muscle serum are 



MEATS AND EGGS. 185 

not the same as those of the muscle plasma that exists in 
the living muscle. Shortly after an animal is killed its 
muscles become hard and stiff. This is caused by a coag- 
ulation of the muscle plasma; during this process the 
coagulable proteids are separated from the non-coagulable 
ones, which can then be expressed with the juice by press- 
ure. This process of separation of proteids is well illus- 
trated in the clotting of blood. It will be seen, then, that 
beef juice does not represent all the proteids of meat, but 
only a portion of them. 

Another process of preparing beef juice consists of 
cutting the meat into small pieces and pouring over it 
cold water, which dissolves out some of the soluble mat- 
ter, and then pressing. Such juice is poorer in solids 
than the expressed juice. 

Expressed beef juice contains, according to different 
authorities, quoted by Hutchinson, from two per cent to 
seven per cent of proteid coagulable by heat. 

As a nutrient beef juice is not of great value, because 
not enough can be given to furnish sufficient nourish- 
ment, as it has a tendency to cause looseness of the bow- 
els. It has, however, a great value as a digestive stimu- 
lant when given with other foods, as the extractives and 
salts it contains have a powerful effect in stimulating the 
appetite and flow of digestive juices. The red color of 
meat is caused by oxyhemoglobin, and as some of this 
passes into the meat juice it has a certain value in fur- 
nishing iron in addition to its nutritional and stimulating 
properties (152). 

no. Meat Extracts. — If lean beef, cut into small 
squares, is placed in cold water, a large part of the albu- 



1 86 INFANT FEEDING. 

mins, globulins, extractives, and salts will dissolve. If the 
meat is expressed and removed, a diluted beef juice re- 
mains. Boiling this juice coagulates the albumins and 
globulins. When the coagulated matter is removed, a 
clear beef tea or soup remains which contains the extrac- 
tives and salts of the meat that give it flavor, but little or 
none of its nutritive elements. When this clear tea or 
soup is evaporated to a semi-solid consistency, the product 
is called extract of beef . It has all the flavor of the beef, 
while the meat from which it was made is almost taste- 
less. In making meat extracts, beef is used in preference 
to other meats because it contains a larger proportion of 
extractives and salts. 

Many believe that the strength and value of meat lie 
in these extracts and that the meat from which they are 
made is worthless; but this is not the case. At the close 
of the Spanish-American war there was an investigation 
into the process of preparing the so-called canned roast 
beef that was furnished to the American soldiers and 
sailors, owing to the charges that it was tasteless stuff 
made of extracted meat and therefore worthless. This 
meat was first parboiled to cause it to shrink and thus 
drive off much of the water it contained; it was then 
placed in cans and cooked again and the cans were sealed. 
In the course of this investigation large quantities of meat 
were put through the process of canning before the court 
of inquiry, and samples were taken at each stage of the 
process and analyzed. A single illustration will suffice to 
show what changes took place in the cooking process and 
the quantity of nutriment extracted. The meat was 
placed in water at 50 F. and steam injected. In five 



MEATS AND EGGS. 



187 



minutes the temperature reached 122 F., and in eleven 
minutes reached the boiling point. The meat was then 
boiled for one hour. 

598 Pounds of Fresh Beef Boiled One Hour. 



Composition of Beef. 

Pounds. 

Water 414. 6 

'Coagulated 75.9 



Proteids 



Globulins 
Proteose 
Peptones 
Gelatin 



Meat bases . . . 

Fat 

Ash 

Undetermined. 



18.3 

6-3 

6.7 
63-9 

6.8* 

5-5 



Extracted by Boiling. 

Pounds. 

Water 243. 2 

Coagulated 

Globulins 

Proteids \ Proteose \ 

Peptones > 1.3 

Gelatin ) 



Meat bases 

Fat 

Ash 

Undetermined . 



3-4 
39-2 
4-2f 



In this test the shrinkage amounted to 46.49 per cent 
of the fresh meat. Practically no proteids were ex- 
tracted. 

From this 598 pounds of beef 1 ,500 pounds of " soup 
liquor" were obtained, which had the following compo- 
sition : 

Solids 0.92 per cent. 

Proteids 09 " 

Meat bases 23 " 

Ash 28 " 

Sodium chloride 11 " 

This soup liquor when evaporated down is used in the 
manufacture of beef extract. It is easy to see that the 
extract of beef will have little or no nutritive value, but 
the claims of the manufacturers that one pound of beef 
extract represents one hundred pounds of beef is not 
far from correct. Boiled meat may be tasteless, but its 
nutritive value is not diminished to any extent. 

in. Meat Broths. — If finely divided meat and cracked 

* Sodium chloride, 1.5 pounds. f Sodium chloride, 1.6 pounds. 



i88 INFANT FEEDING. 

bones are boiled for a long time the connective material 
of the meat and the cartilaginous materials of the bones 
are converted into gelatin, which is soluble in hot water. 
Broths so made usually gelatinize on cooling. They con- 
tain the salts and extractives of the meat in addition to 
the gelatin. If the meat which is disintegrated is not 
strained off, the nutritive value of the broth will be in- 
creased just so much. In preparing broths the bones of 
young or small animals which are not so ossified as those 
of older animals yield best results. Hence the wide use of 
chicken, veal, and mutton for this purpose. These broths 
have a useful place in infant dietetics when milk must 
be withheld, especially when prepared with cereals (154). 

112. Beef Preparations. — Within the past few years 
there has been an increasing number of beef preparations 
on the market. These may be divided into three classes : 

I. Beef extracts prepared from "soup liquor" or other 
meat as just described. These should be looked upon as 
flavoring agents. 

II. Beef juice prepared by expressing meat as previ- 
ously described (109). These have about the same value 
as home-expressed beef juice. 

III. Predigested beef, which is composed of albumoses 
and peptones produced by the articial digestion of beef. 

As meats play so small a part in infant feeding, these 
preparations have not a wide use and will not be de- 
scribed. 

Eggs. 

113. It is a remarkable coincidence that eggs are as 
highly specialized in their composition as it has been 
shown that milks are (6, 31). 



MEATS AND EGGS. 



189 



Eggs are divided into two great classes. 

I. Those from which the young birds emerge devel- 
oped sufficiently to move about and feed themselves. 
Example, hen's eggs. 

II. Those from which the young birds emerge in a 
helpless condition and need further development before 
being able to move about and feed themselves. Exam- 
ple, robin's and sparrow's eggs. 

There are wide differences in composition between 
these two types of eggs. 

Hen's eggs have a useful place in feeding infants and 
young children, as they contain large quantities of cell- 
building materials (2, 3). 

The weight of eggs, according to Hammarsten, varies 
between 40 and 60 gms. 

The yolk weighs 12 to 18 gm. and contains, accord- 
ing to Parkes, quoted by Hammarsten: 

Water 47 . 1 9 per cent. 

Proteids 1 5 . 63 

Fat 22. 84 

Lecithin 10. 72 

Cholesterin 1.75 

Salts insoluble 3.53 

Salts soluble 6. 12 

The white weighs 23 to 34 gms., and contains, ac- 
cording to Hammarsten: 

Water 85 to S8 per cent. 

i Ovalbumin \ 
Ovaglobulin j- 10 to 13 " 
Ovamucoid ) 

Salts 0.7 " 

Fats 1 

Soaps 

T .... y Trace. 

Lecithin 

Cholesterin 



190 INFANT FEEDING. 

There are many subdivisions of these ingredients of 
both the yolk and white of eggs that are not of interest 
here. It will be noticed that there is an absence of carbo- 
hydrates in eggs. The function of carbohydrates in food 
is to furnish heat. As the mother bird sits on the eggs 
and keeps them warm during incubation, the developing 
chick has little need for heat-producing food, and it is not 
found in eggs. Whole eggs may be looked upon as a 
tissue-building food, but not as a complete food ; for in- 
fants or adults need in addition liberal quantities of carbo- 
hydrates. 

White of egg should not be used as the sole source or 
main source of proteid for infants, as it cannot build up 
cells. Experiments in feeding animals with white of egg 
have shown it not able to support life. In certain 
forms of indigestion it may be used temporarily with 
benefit. 

Flavor of Eggs. — The flavor of eggs may be the result 
of two causes : i . From the hens eating highly flavored 
or animal food. 2. From changes that take place in 
eggs that are kept for any length of time, probably due 
to bacterial infection. 

Market Eggs. — Eggs for the New York market, and 
probably for other large cities, come from a wide area of 
country and are divided into four grades. 

First Grade, or Hennery Eggs. These are from se- 
lected breeds of fowls and are from three to five days old 
when sold. 

Only a few high-grade stores have these, and they 
bring from ten to fifteen cents a dozen above the price of 
the next grade. 



MEATS AND EGGS. 191 

Second Grade, or New Jersey, New York, and Penn- 
sylvania State Eggs, which are about a week old when 
they arrive in New York. These are what would be gen- 
erally called first-class eggs and are kept by the best 
stores. 

Third Grade, or Packing Eggs. These are from Illi- 
nois, Indiana, Iowa, Michigan, and Ohio, and are at least 
two weeks old when they arrive in New York. These 
are the eggs found in the general run of stores. 

Fourth Grade, or Kentucky, Missouri, and Tennessee 
Eggs. The hens that produce these eggs are not care- 
fully fed, being allowed to run at large and eat anything 
they can find, consequently the eggs are strong in flavor 
and watery and spoil easily. These are the cheapest 
eggs that are sold. 

Preservation of Eggs. — As the shells of eggs are por- 
ous, bacteria find their way into eggs and set up putrefac- 
tive changes which soon spoil them. If the egg lies on 
one side too long the yolk will move to that side and stick 
to the shell. To preserve eggs from these changes they 
are often kept cool or immersed in a solution of silicate 
of soda (water glass) or lime water, which fills up the 
pores. Eggs kept in silicate of soda solution have been 
kept three and one-half months without apparent change 
in flavor or in position of the yolk. When such eggs are 
boiled, they are apt to burst open as the steam generated 
inside the shell cannot escape through the closed pores. 
To overcome this objection egg dealers prick the 
shell. 

Candled Eggs. — A perfectly fresh egg, when held be- 
fore a candle in a dark room, appears almost translucent. 



i 9 2 INFANT FEEDING. 

Cloudiness denotes a change in the egg; when decayed 
or rotten, it appears very dark or black. This is a very 
simple way of selecting fresh eggs. An absolutely fresh ' 
egg should be obtained in order to get a clear idea of how 
it appears. 



PART III. 



CHAPTER XIX. 

BREAST FEEDING — DIET AND CARE OF 
MOTHER — ELIMINATION OF DRUGS IN 
MILK-CARE OF NIPPLES— CONTRAINDICA- 
TIONS— MENSTRUATION— P REGNANCY— 
WET-NURSING — WEANING AND MIXED 
FEEDING. 

114. When it is possible for the mother to nurse her 
offspring, comparatively little difficulty will usually be 
experienced in properly nourishing the infant. In view 
of this fact all possible foresight should be used in fitting 
the prospective mother for her duties. 

For several months before expected delivery, the nip- 
ples should be gently rubbed between the thumb and fin- 
gers, depressed or misshapen nipples being thereby drawn 
out and developed ; this also toughens them and prevents 
possible tenderness or fissure that would interfere with 
nursing. Tight clothing over the breasts should be 
avoided. Bathing the nipples with boric acid or borax 
solution, one-half teaspoonful to a cup of water, promotes 
cleanliness and thereby tends to avoid possible infection 
and soreness during the nursing period. 

After the mother is sufficiently rested from the labor 
the baby should be put to each nipple. If this does not 
satisfy, and the infant becomes fretful or restless, a tea- 
spoonful or so of boiled water may be given. This not 
only quiets the infant, but helps to wash out the digestive 



196 INFANT FEEDING 

tract and kidneys. For the first day or two the infant 
may be put to the breast at three-hour intervals during 
the day and at four- to six-hour intervals at night; after 
this every two hours during the day and once or twice at 
night. The infant should not be allowed to occupy the 
bed of the mother at night, as this is a common cause of 
too frequent nursing. Regularity of feeding is essential, 
as the composition of milk varies with unequal intervals 
between nursings. The shorter the intervals, the richer 
the milk is in fat, so it is well each day to write down the 
hours at which nursings are to be given, as 5, 7, 9, 11 a.m., 
1,3,5,7,9 p.m., etc. When the amount of milk is suffi- 
cient, the baby will suckle for fifteen or twenty minutes 
and then drop off contentedly to sleep. If, on the con- 
trary, the baby tugs at the nipple for twenty-five or thirty 
minutes, and then frets after leaving it, there has not been 
sufficient milk secreted. 

1 15« In cases in which the milk flow is scanty or does 
not agree with the infant, particular attention should be 
paid to the diet and hygiene of the mother. Southworth, 
who has made a special study of this subject, states that 
much more than is generally believed can be accomplished 
in this direction. Nursing is a purely animal function 
and a great deal can be learned from the study of the 
secretion of milk by cows. Here it has been found that 
secreting milk is hard work, and that a cow in milk needs 
as much food as an ox doing heavy work. The best cow 
is one whose digestive and excretory systems are highly 
developed and who has no tendency to lay on fat. Such 
a cow is virtually a milk manufactory. 

Therefore it is useless to expect any mother to supply 



BREAST FEEDING. 197 

thirty to forty ounces of milk daily, containing about five 
ounces of solids, the proteid of which is equivalent to 
about a quarter of a pound of meat, unless she eats and 
digests a liberal quantity of food. 

The diet of the mother should consist of plenty of 
plain, easily digested food, meat, milk, eggs, and well- 
cooked cereals (102) predominating. Tea and coffee 
should be withheld, as they have a tendency to diminish 
the feeling of hunger and thus cause less food to be eaten 
and digested, while cocoa and chocolate may be drunk 
in moderation. Liquid malt extracts may have a benefi- 
cial effect by toning up the digestive system, thereby en- 
abling more food to be digested, but not by any particular 
property of making milk. Southworth recommends to 
have the mother drink between meals a bowlful at a time 
of a well-cooked and salted gruel made from yellow corn- 
meal. This not only contains nourishment and water 
that is needed, but undoubtedly has by its coarse particles 
a beneficial effect in increasing the amount of faecal mat- 
ter (27) and thus keeping the bowels regular. 

116. It is well known that volatile substances in food 
readily find their way into milk and that the flavor of a 
cow's milk is often affected by her food ; also that under 
certain conditions urea is found in appreciable quantities 
in milk. For these reasons highly flavored food should 
be avoided and strict attention should be paid to the 
excretory organs, so that products shall not be thrown off 
with the milk which should pass off in the urine. 

Constipation in the mother should be overcome by 
the use of drugs if copious quantities of the cornmeal 
gruel do not relieve this condition. In selecting drugs 



198 INFANT FEEDING. 

for this purpose, those whose principal action is on the 
muscular coat of the bowel, rather than on the glandular 
apparatus, should be chosen. Cascara is one of the best 
for this purpose. Anaemia should be overcome by gen- 
erous diet and the exhibition of iron. 

Great care must be exercised in the administration of 
drugs to nursing women, as they may be excreted in the 
milk. Thus morphine, mercury, quinine, iodide of pot- 
ash, and similar preparations, may have a marked effect. 
This is especially apt to happen when the mother is in a 
disturbed condition, and consequently the excretory or- 
gans and mammary glands are not in a normal state of 
equilibrium. 

117. The great and sudden variations in composition 
of milk are the result of nervous influences, and as diges- 
tion is also greatly affected by anxiety, fright, fear, or 
other nervous disturbances, particular attention should be 
paid to keeping the mother in a cheerful state of mind 
and to seeing that her rest at night is not too much broken. 
As fresh air is very invigorating, a walk that stops short 
of fatigue or a drive with pleasant company will have a 
beneficial effect. 

118. In cases in which the mother or nurse is robust 
and has a plentiful supply of milk that disagrees with the 
infant, it may prove advantageous to cut down the diet, 
particularly of proteids (meat, eggs, etc.), as they have a 
tendency to increase the percentage of fat and proteids 
in the milk. With the reduction of diet should go an 
increase of exercise, causing to be used up some of the 
excess of food eaten, and possibly the exhibition of sa- 
line cathartics. 




BREAST FEEDING. 199 

If, with the means indicated, it is impossible to keep 
the infant steadily gaining in weight, four to six ounces a 
week, with good digestion and normal stools (156), one or 
two artificial feedings, alternating with breast feedings 
when possible, should be given daily, as 
will be explained later (122). 

119. When from fissured nipples or 
other causes it is impossible for the 
infant to nurse, the milk may be drawn 
with a breast pump and fed by bottle or 
medicine dropper for a few days, until 
a return to breast feeding is possible. 

If an abrasion or slight fissure of 
the nipple causes much pain to the mother, the use of the 
nipple shield for a day or so may give great comfort and 
allow healing to take place. The infant often rebels 
against its use, however, from the difficulty of pulling the 
milk through. The latter may be partly obviated by fill- 
ing the shield with warm water at the start, and at the 
same time massaging the breast, thus getting an easy 
flow of fluid. Between nursings the 
nipple must be carefully protected. 

120. Contraindications /or Nurs- 
ing. — Mothers with certain constitu- 
,-Breast shield. donal diseases> especially tuberculosis, 

should not be allowed to nurse their offspring. When 
the mother is pale and losing flesh and exhausted by 
suckling in spite of tonic treatment, the baby must not 
be continued on the breast. In nervous, excitable women, 
when every effort has been made to regulate the details 
of diet and living, and yet the baby does not thrive 




200 INFANT FEEDING. 

and gain after a fair trial, it is best to stop the 
breast. 

Nursing after Menstruation. — The question of nursing 
after menstruation has been resumed can usually be 
answered in the affirmative. Any disturbance is usually 
only temporary and may not recur at the next period. 
If, however, severe nervous and digestive disturbances 
regularly occur at each period and interfere with the nu- 
~~^~ trition of the infant, it may be neces- 

sary to remove the breast entirely. 
Before this is done a trial may be made 
of giving the bottle during the time 
of menstruation and then resuming 
the breast. 

Intervening Pregnancy. — If preg- 
nancy intervenes it is usually best to 
give the baby other nourishment. 
There may be many exceptions, how- 
ever, to this rule. Thus, if pregnancy 
occurs during the middle of a hot 
summer, when the baby is thriving, or 
in the case of a weak fragile baby with 
a tendency to digestive trouble, the breast may be con- 
tinued during the early period of pregnancy; while not 
ideal, this may prove the best method of feeding available. 
121. Wet-Nursing. — In many cases in which a mother 
cannot nurse her infant, a wet-nurse is the best substitute. 
A wet-nurse is especially indicated when the infant is 
poorly developed and shows signs of digestive feebleness. 
The preferable age for the nurse is between twenty and 
thirty years, and multiparas usually do better than primi- 




BREAST FEEDING. 201 

paras, the former having had previous care of the suckling 
and general charge of infants, which may be of decided 
advantage. 

Too much disparity between the ages of the infants 
is not desirable, but a woman whose infant is under six 
months can usually suckle a new-born baby. One advan- 
tage of having a wet-nurse with an older infant is that 
a careful inspection of the nurse's infant will show how 
well it has thriven upon her milk, and also whether it 
has derived any constitutional disease, especially syphilis, 
from the mother. In every case a careful physical exam- 
ination of the applicant, as well as her infant, should be 
made by the physician. As changes in the composition 
of milk are largely the result of nervous influences and 
changes of diet, a woman of quiet, phlegmatic tempera- 
ment, in good health, is to be preferred, and when selected 
her diet should be as nearly as possible that to which she 
has been accustomed, and she should not be allowed to 
remain in idleness. A, routine life should be established 
and maintained, as this will insure a uniform milk. The 
nurse's reward should be in some other form than grati- 
fication of her inclinations. This reward should be held 
out as an inducement for her to comply with directions. 
After her services are no longer required, she can obtain 
what she likes with the money she has earned ; but if she 
is furnished a diet she is unaccustomed to, she will in all 
probability over-eat and bring on either defective diges- 
tion or excretion, which will promptly disorder the diges- 
tion of the infant. 

Several nurses will sometimes have to be tried before 
a breast that completely agrees with the baby is found. 



202 INFANT FEEDING. 

122. Weaning and Mixed Feeding. — Many women who 
are good nurses show a deficiency in their milk, either in 
quantity or quality, by the eighth or ninth month. The 
bottle can here be given with advantage several times 
during the twenty-four hours, and especially at night, so 
that the breast can have a prolonged rest. The rate of 
gain in weight of the baby and the health of the mother 
will be the gauge as to when mixed feeding should be 
begun. In any case the baby should be removed entirely 
from the breast at the end of the first year. Toward the 
end of lactation the milk becomes unsuitable in composi- 
tion. This will be shown either by digestive disturbances 
or loss of weight, or both, on the part of the baby. Wean- 
ing should be gradual, and as most babies will require the 
help of the bottle during the latter part of lactation, it is 
well to begin as soon as possible in giving one or two 
bottle feedings each day ; the baby will then be educated 
in its use, the mother will have more time to herself, and 
in case of her being ill, sudden weaning will not be neces- 
sary. If this method is employed, the change from breast 
feeding to bottle feeding will not cause inconvenience. 

Examination and Modification of Breast Milk. 

123. In cases in which the mother's milk does not agree 
with a baby, as shown by constant colic, or stationary or 
losing weight, the breast should not be withdrawn until 
every effort has been made to find out and correct the 
cause of the trouble. Rotch has shown by repeated chem- 
ical analyses of mother's milk that much may be accom- 
plished by altering the diet and habits of life to render 
breast milk, when disagreeing, more fit for any given 



BREAST FEEDING. 



203 



n 



\ 



case. Each case must be carefully studied in every detail 
before finally deciding to remove the baby from its 
mother's breast. There is no doubt that a large number 
of infants suffer from premature removal ; often with a 
little care and patience lactation could be continued dur- 
ing the normal term. 

The careful studies and analyses of 
Rotch have also shown that nervous, emo- 
tional women, or those who nurse their 
infants at prolonged or irregular intervals, 
or too frequently, or who are disturbed 
at night are apt to furnish a poor milk. 
Regularity in diet, excretion, exercise, 
rest, and nursing are always to be insisted 
upon ; sometimes it may be necessary to 
have the mother sleep in a room where 
she cannot be disturbed 'by the infant 
for a few nights, feeding it then by bottle. 
If, after these precautions have been taken, 
the milk continues to disagree, an analysis 
may throw light on the cause of the diffi- 
culty. Many analyses of human milk show 
it generally to contain fat 3 to 5 per cent, 
proteids 1 to 2 per cent, and sugar 6 to 
7 per cent. Undoubtedly there is con- 
stant changing and variation in these 
percentages within certain limits, from 
and even from hour to hour, but the 



W 



Fig. 54. — From 
Holt's "Infancy and 
Childhood." (Copy- 
right, 1897, by D. Ap- 
pleton & Co.) 



day to day, 
infant usually 

adapts itself to these variations, that doubtless per- 
form a useful function in the nutrition of the child. 
It is found that variations are mostly in the fats 



204 



INFANT FEEDING. 




and proteids, the sugar remaining quite constant in 

quantity. 

i. If fats and proteids are both low the infant is not 

getting enough nourishment, and of course cannot gain 
in weight. A more liberal diet for the 
mother is indicated. 2. If fats are low 
(below three per cent), and the proteids 
normal (one to two per cent), the mother 
must be fed more meat, eggs, and milk. 
It is useless to feed her excess of fats, as 
they will interfere with her digestion. 3. 
If proteids are high (above two per cent) 
the mother's meat and milk diet must be 
cut down. 4. If fat and proteids are both 
high, the diet must be cut down, partic- 
ularly the meats, and a liberal amount of 
out-of-door exercise must be taken. A 
brisk walk of a mile or two in the open 
air, twice daily, will sometimes correct an 
overrich milk. The physician must, how- 
ever, be specific in his orders, as exercise 
to the point of fatigue may be required 
to get results. 

\\ nen a complete analysis of the milk 
cannot be had, an approximate analysis 
may be made by the fat and solids not fat 
tests, described in the chapter on testing 

cow's milk. The fat is determined by the Babcock test, 

and the specific gravity with an ordinary urinometer. 

About an ounce of milk is required. The entire contents 

of a breast should be removed and mixed, or very errone- 



F 1 G. 55. - From 
Hch's "Infancy and 
Childhood." (Copy- 
right. 1897, by D. Ap- 
pleti m & Co.) 



BREAST FEEDING. 



205 



ous impressions will be obtained, as the fat varies greatly 
in different portions of the secretion. 

Holt has devised an apparatus, consisting of a cream 
gauge and a small hydrometer, for testing as small a 
quantity as one-half an ounce of breast milk. 

The specific gravity is taken at 70 F., and the milk 
placed in the cream gauge ; after twenty-four hours the 
percentage of cream may be read. Five per cent of cream 
corresponds to three per cent of fat. The interpretation 
of results is shown in the following table by Holt: 

Woman's Milk. 



Specific gravity, 70 F. 



Cream — 24 hours. 



Proteids (calculated). 



Average 

Normal variations . . 
Normal variations . . 
Abnormal variations 

Abnormal variations 

Abnormal variations 

Abnormal variations 



1. 031 

1.028-1.029 

1.032 

Low (below 1.02S) 

Low (below 1.028) 
High (above 1.032) 
High (above 1.032) 



7% 

8 to 12% 

5 to 6% 

High (above 10$) 

Low (below 5$). . 

High 

Low 



1-5%. 

Normal (rich milk). 

Normal (fair milk). 

Normal or slightly be- 
low. 

Very low (very poor 
milk). 

Verv high (very rich 
milk). 

Normal (or nearly so). 



CHAPTER XX. 

METHODS OF SELECTING FOOD FOR ADULTS 
NOT APPLICABLE TO INFANTS— NUTRI- 
TION AND DEVELOPMENT OF THE DIGES- 
TIVE TRACT MUST BE CONSIDERED TO- 
GETHER. 

124. When it becomes impossible to supply an infant 
with its mother's milk or that of a suitable wet-nurse, re- 
course must be had to some substitute food. This may 
be done in two ways: (1) By telling the mother or nurse 
to try everything that is suggested by kind friends until 
something is found that " agrees " ; or (2) scientifically to 
adjust the food so that the infant's future well-being will 
be conserved. 

A. V. Meigs, of Philadelphia, made the first attempt at 
scientific infant feeding by trying to adjust or modify 
cow's milk so that it would resemble mother's milk in 
composition. Later, Rotch, of Boston, emphasized the 
importance of systematic "percentage feeding," which 
consists of trying to make from cow's milk a mixture that 
contains accurate percentages of fat, proteids, carbohy- 
drates, mineral matter, and water, and varying these per- 
centages to suit the requirements of each particular in- 
fant. Other workers have contributed their quota to the 
advancement of scientific infant feeding with the result 
that many formerly accepted beliefs and doctrines have 



FOOD FOR ADULTS INAPPLICABLE. 207 

been modified or completely abandoned. At present it 
is not accepted that there is one, and only one, way of sci- 
entifically feeding an infant. While there may be differ- 
ences of opinion as to methods of feeding, there are cer- 
tain principles involved which are beyond dispute and 
about which there can be only one opinion. 

125. It has been shown (1) that true growth consists 
principally of an increase of protein in the body by a proc- 
ess of cell division (2), and the addition of mineral mat- 
ter to the bones. (2) That protein cannot be elaborated 
by the infant, but must be taken in as such with the food. 
(3) That there are many forms of protein, some of which 
are not tissue builders and can only put off the time when 
death will result from starvation (24). (4) That the first 
demand of the animal organism is for heat-producing food, 
and that during starvation normal heat is kept up by de- 
struction of the tissues (22). (5) That the function of 
fat and carbohydrates in the body is to produce energy 
and heat (19). 

It follows that one of the first problems of scientific 
feeding is to determine the quantities and quality of the 
protein (tissue builder) and fat and carbohydrates (heat 
producers) needed for a given individual. This problem 
has been pretty well worked out for adults, and is gener- 
ally performed as follows: 1. From the quantity of ni- 
trogen in the urine during a period of fasting is deter- 
mined the amount of protein used up daily. There is 
no advantage in feeding more than this quantity to an 
adult as it is only excreted (20). 2. From the quantity 
of oxygen consumed is calculated the quantity of heat 
produced. 



208 INFANT FEEDING. 

The standard for measuring heat values in dietetics is 
called a large caloric and is the amount of heat required 
to raise the temperature of one litre of water (2.2 lbs.) 
i° Cor i.8° F. 

The heat produced by the combustion of 1 gm. of 
protein is about 4.1 calories; of 1 gm. of carbohydrates, 
about 4.1 calories; of 1 gm. of fat, about 9.3 calories, or 
about two and one-quarter times that of either protein or 
carbohydrates. 

It has been found that a man doing ordinary muscu- 
lar work requires daily about 125 gm. (= 4 oz.) of protein * 
and enough other food to produce about 3,000 calories. 
In selecting the food for such a man it is only necessary, 
theoretically, to see that his food contains 125 gm. of 
digestible protein and enough heat-producing food to pro- 
duce 3,000 calories. Adding the results obtained by mul- 
tiplying by 4.1 the weight in grams of the protein and 
carbohydrates, and by 9.3 that of the fat contained in any 
food, will give the total number of calories it will 
produce. 

Tables have been prepared showing the composition 
of most articles of food in general use, expressed in per- 
centages of digestible protein, fat, and carbohydrates, and 
it is a simple matter to calculate from these analyses the 
quantities required properly to nourish a person. 

For a healthy adult there are many articles of diet that 
are interchangeable, weight for weight almost, as their 
composition and digestibility are practically the same ; for 
this reason it makes little difference which article is 
used. 

*It is claimed by Chittenden that this quantity is more than is necessary. 



FOOD FOR ADULTS INAPPLICABLE. 



209 



The following analyses by Atwater illustrate this 
statement : 




Fat, per cent. 



Corned rump of beef. 

Turkey 

Shoulder of veal 

Halibut 



5-i 
5-9 
7-9 
4.4 



In preparing food for infants this method of selecting 
food cannot be employed, as will be explained further on. 

The proportion between the digestible protein and 
heat-producing elements in food is called the nutritive 
ratio and is thus determined. As fat has about two and 
one-quarter times as much fuel value as carbohydrates, 
the weight of the fat is multiplied by two and one-quarter 
and added to the weight of the carbohydrates. The pro- 
portion between the weight of the protein and the weight 
of the heat producers, calculated as carbohydrates, is the 
nutritive ratio. 

Example. A food contains: 

Fat, 2 per cent; protein, 10 per cent; carbohydrates, 50 percent. 
Fat, 2 per cent X 2^ = 4-5 per cent, equivalent in carbohydrates. 
Carbohydrates, = 50.0 per cent 



Nutritive ratio, 1-5.45. 



54.5 per cent -f- 10 per cent protein = 5.45. 



This is about the ratio required by adults. 

There is a wider nutritive ratio in human milk, which 
we should strive to imitate, than in an adult's food, as can 
be seen by a glance at analyses of this milk that are 
within the range of variation: 

Human Milk. 



Fat, per cent. 



Proteid, per cent. 



Sugar, per cent. 



Nutritive ratio, I-I5 
Nutritive ratio, 1-8. 



14 



210 INFANT FEEDING. 

In human milk not only is there a variation in compo- 
sition, but also in the nutritive ratio. The much greater 
proportion of heat-producing elements in the infant's nat- 
ural food than in the adult's food is in part accounted 
for by the fact that there is a much greater radiation of 
heat from an infant's body; metabolism is also much more 
active. 

At first thought nothing seems more rational in arti- 
ficial infant feeding than taking the milk of some of the 
lower animals and adjusting the percentages of fat, pro- 
teids, and sugar, and the nutritive ratio, so that they shall 
approximate those of human milk. Adjusting diets for 
adults on this percentage and nutritive ratio plan is very 
successful, but unfortunately not so successful in feeding 
infants, as it is often impossible for a young infant to 
digest the same percentage of the proteids of cow's milk 
as is found in woman's milk. 

In feeding adults, in whose fully developed digestive 
systems a great variety of foods can be digested equally 
well, it is only necessary to see that enough of fat, pro- 
teids, and carbohydrates are furnished to maintain the 
body. 

In feeding infants or young animals, whose digestive 
systems are not fully developed, it is not only necessary 
to supply the proper quantities of nutritional elements, 
which include such ingredients as fat, proteids, carbo- 
hydrates, and mineral matter, but they must be in such 
form as normally to develop the digestive tract. 

It has been shown in chapters IV. and VIII. that the 
milk of each species of animal is highly specialized for these 
two purposes. For these reasons it is not to be expected 



FOOD FOR ADULTS INAPPLICABLE. 211 

that a perfect substitute for human milk will ever be pro- 
duced. The most that can be done is to provide a food 
whose composition is as nearly like human milk as our 
imperfect knowledge of milk permits us to make, and to 
have it in such form that it will allow a normal use and 
development of the digestive tract. 

126. Development of the Digestive Tract. — In chapters 
iv., viii., it was shown that all animals are similar in the 
early stages of their development, but that as they become 
more developed they assume the characteristics of the par- 
ents. The digestive tracts are all alike and simple in 
these early stages and also become specialized as develop- 
ment progresses. When a young suckling animal is born 
it has never used its digestive tract, the cells of the body 
having been nourished by the blood stream of the mother. 
The process of absorption of food from the digestive tract 
takes place principally in the intestines, and the first secre- 
tion of the mammary glands is not milk but colostrum, 
which is quite different from milk, in that it requires little 
digestion and does not form curds in the stomach. Co- 
lostrum contains the same general food elements as milk 
— fats, proteids, carbohydrates, mineral matter, and water 
— but in different Jorms. It can be absorbed with little 
effort, as its proteids are soluble and the sugar is dextrose 
and not the sugar of milk. The function of colostrum 
seems to be to furnish nourishment and to start up the 
digestive process of the intestines. In the course of a 
few days after birth the character of the mammary secre- 
tion begins to change. The soluble proteid and dextrose 
of colostrum are largely replaced by casein and milk sugar, 
and normal milk secretion is established. A peculiar and 



212 



INFANT FEEDING. 



distinguishing constituent of colostrum is the presence 
of colostrum corpuscles < Fig. 56). Colostrum will coagu- 



late when boiled. 



When the mammary secretion shows 
no colostrum corpuscles 
and does not coagulate 
when heated it is said 
to be milk. It may be 
ten to twenty days after 
birth before colostrum 
is entirely displaced by 
milk (Figs. 56, 57, and 
58). 

This secretion of co- 
lostrum and gradual dis- 
placement by milk is 
common to all suckling 
animals, but when the milk flow is established wick dif- 
ferences in the character of the milk secreted by differ- 
ent animals are found. 




Fig. 56.— Colostrum Bodies. (X 300.) a'. Cells 
with nucleus ; a, cells undergoing fatty degenera- 
tion ; b, cells containing large drops of fat ; <r, cells 
with a partially destroyed cell membrane ; d, e. and /, 
cells which have entirely lost the cell membrane ; g, 
cell masses from the milk canals. (Aikman.) 




Fig. 57.— Normal Human Milk. (Jewett.) 



Fig. 5S. —Colostrum Corpuscles. (Jewett.) 



FOOD FOR ADULTS INAPPLICABLE. 213 

During the colostrum period there is little secretion of 
digestive juice in the young animal's stomach. As the 
milk begins to displace the colostrum the stomach of the 
young animal begins to secrete rennet, a ferment which 
acts upon the casein of milk, changing it into paracasein, 
which is a solid or gelatinous mass or curd, depending on 
what kind of milk is acted upon. Junket, the familiar 
dessert, is cow's milk in which the casein has been changed 
into paracasein by rennet. The milk of animals whose 
digestion takes place principally in the stomach forms 
solid curds that leave it with difficulty (cow's, goat's and 
sheep's milk). The milk of animals whose digestion is 
principally intestinal forms soft gelatinous curds which 
easily pass into the intestines (mare's and ass' milk). 
The human digestive tract stands between these two 
types, and consequently neither cow's nor ass' milk 
fits it. 

The rennet, acting upon the milk, changes it into a 
semi-solid mass much like chyme which is ready to be 
passed into the intestines. The pepsin of the stomach 
will not attack the curds formed by the rennet. When 
hydrochloric acid is secreted by the stomach it combines 
with the rennet curds — paracasein — and forms compounds 
which are readily acted upon by pepsin. As more acid is 
secreted it combines with more of the rennet curds and 
gives more work for the pepsin secreted. In this way the 
work of the stomach increases as fast as its secretion of 
digestive juice increases ; mother's milk thus automatically 
adapts itself to the normal young animal's digestive ap- 
paratus. If mother's milk did not alter to meet the in- 
creased quantity of the digestive juices, the infant's stom- 



214 



INFANT FEEDING. 



ach would find less work as it grew stronger, with conse- 
quent atrophy. 

For this reason the feeding intervals become longer as 
the infant grows stronger. While at first little digestion 
takes place in the stomach, as the digestive secretions of 
the stomach become greater they alter the milk so that it 
requires gastric digestion, and consequently the stomach 
does not empty as rapidly. 

I Hiring the suckling period the infant should be looked 
upon as being a foetus and not as a perfectly formed hu- 
man being. That this view is the correct one is evidenced 

by the lower forms of animal 
life in which there is no pla- 
cental connection between 
the parent and young, but a 
mammary attachment, the 
foetus growing fast to the 
teat and being nourished by 
mammary secretion ejected 
by the mother into the gullet, 
long before it is developed 
sufficiently to suck, when it 
ceases to be adherent to the 
teat and sucks at will, much 
as any other young animal 
(Figs. 10-12 and 59). 

During the suckling pe- 
riod of the kangaroo its di- 
gestive tract changes greatly and there can be no doubt 
that the mother's secretion adapts itself to the altered di- 
gestive tract (6, 32 B). 




Fig. 59. — Head of Mammary Foetus of 
Kangaroo Hemi-sected to show Adaptation 
of Teat to Mouth. See also Figs. 10 to 12. 
Life size. (Photograph of specimen in the 
Zoological Collection of Columbia Univer- 
sity.) 



FOOD FOR ADULTS INAPPLICABLE. 215 

To recapitulate: colostrum develops the absorptive 
process of the intestines ; the casein of the milk, by being 
changed by the rennet of the stomach into a solid or semi- 
solid, develops the motor function of the stomach, and by 
combining with the acid of the stomach as fast as it is 
secreted, develops the chemical function of the stomach. 

After the stomach is developed, teeth appear and the 
mechanical portion of the digestive tract (5) is still fur- 
ther developed, weaning takes place, and the infant be- 
comes independent of its mother's body. In the infant, 
the development of the digestive tract covers a period of 
about two years, so it is manifestly out of the question to 
use methods of selecting food for infants that are adapted 
for adults. It should be remembered that nature has no 
one food for the infant, but that the mother adapts the 
food to the state of development of the baby, at one time 
even changing the character of the proteid and sugar 
secreted by the breast. The great underlying principles 
of infant feeding consist in furnishing sufficient food and 
adapting it to the state of the infant's digestive tract. 
What nature does automatically must be imitated by the 
most successful feeders. 

It must be clearly borne in mind in infant feeding that 
nutrition and development of the digestive tract must be 
considered together. Little progress will be made if only 
a calculation of the composition of food is made. This 
is a small part of scientific infant feeding, although by- 
many writers on the subject an undue amount of atten- 
tion lias been given it, which lias made infant feeding ap- 
pear to be a complicated subject. As a matter of fact, 
when the principles of artificial infant feeding are grasped, 



216 INFANT FEEDING. 

the process becomes as simple as diluting condensed milk, 
and the most scientific food that can be conceived can be 
prepared in any home with very little effort. 

The principles of preparing infant food will be con- 
sidered in the next chapter. 



CHAPTER XXI. 

GENERAL INGREDIENTS OF 
INFANT'S FOOD. 

Breast Milk as Pattern — Effect of High and Low 
Protein — Value of Percentage Feeding — Cream 
and Milk Mixtures — Bottled Milk — Top Milk 
— Diluents. 

127. In preparing an artificial food for infants nature 
should be followed as closely as possible. The food should 
compare with human milk in its nutritive value, which is 
determined by chemical analysis, in physiological proper- 
ties, or its behavior in the digestive tract, and in the man- 
ner and condition in which it is supplied to the infant. 

In composition, human milk is variable, but it is gen- 
erally believed that it contains as a rule between 3 per 
cent and 5 per cent of fat, 1 per cent and 2 per cent of 
proteid, 6 per cent and 7 per cent of sugar, and 0.2 per 
cent and 0.3 per cent of mineral matter. No attempt is 
made to take account of its other ingredients. In its 
physiological properties it is specially adapted for de- 
veloping the infant's digestive tract, owing to the char- 
acter of its protein. 

There has been a great deal of discussion as to what 
forms of protein exist in human milk. Chemists have 
not agreed on this point and with improved methods of 
analysis different results are continually being obtained. 
Some authors call the protein of milk casein or caseinogen 
and lactalbumin, and many analyses have been published 



218 INFANT FEEDING. 

showing the percentages of these ingredients. Other 
chemists, using later and improved methods, have found 
large quantities of other forms of protein, especially in 
woman's milk; also that the casein of human milk has 
not the same properties as that in other milks. Varying 
results have also been obtained in examination of the 
sugar of milk (28). 

Though the composition of the milk of any animal is 
variable and no definite conclusion can be reached as to 
the character of the protein of different milks, one char- 
acteristic stands out clearly, and that is, the protein of 
each milk is especially adapted for the digestive tract it 
was intended to supply. Though young animals readily 
tolerate a variation in quantities of the protein of their 
natural milk, they are promptly disturbed when the pro- 
tein of the milk of another type is supplied to them. The 
fats and sugars cause little trouble. As all young animals 
thrive on their mothers' milk irrespective of its type, and 
as all animal life requires the same ultimate food elements, 
the differences between the milks of different animals 
must be more physiological than chemical. 

None of the lower animals furnishes a milk that ap- 
proximates human milk in physiological properties even 
after the percentages of fat, proteids, and sugar have been 
adjusted to equal those of human milk. In the breast 
the ingredients of the milk are not secreted uniformly, 
the greater quantity of fat being in the latter part of the 
flow ; furthermore, the milk has not undergone bacterial 
changes. 

In feeding an infant artificially it is impossible to 
secure a food whose ingredients have the same physio- 
logical properties as those of human milk, to imitate the 



INGREDIENTS OF INFANT'S FOOD. 219 

process of secretion, or generally to obtain milk free from 
bacterial change. Therefore it should always be kept in 
mind that any thing aside from breast milk that is put into 
an infant's stomach is a foreign substance that may cause 
digestive disturbance. This is one of the fundamental 
principles of infant feeding. 

128. Though nutrition and development of the diges- 
tive tract should be considered together, nutrition comes 
first, and in cases of poor digestion it is justifiable to use 
anything that will sustain the infant until normal digestion 
is re-established ; then the food should be changed so as 
to cause proper development. Many feel that after some- 
thing that "agrees" and causes gain in weight is found, 
the problem of successful feeding has been solved ; but the 
future of the infant may be completely wrecked by such 
a method of feeding. For instance, an infant is receiv- 
ing as much fat and sugar as is found in human milk and 
only one-fourth to one-half as much protein. The infant 
is fat and gaining in weight, and to all appearances 
healthy, yet it can be predicted with reasonable certainty 
that this infant will become rachitic or succumb to the 
first serious illness. As resisting force comes from the 
protein of the food, it is apparent that a bottle-fed infant 
who receives but one-fourth to one-half as much protein 
as a breast-fed infant will not be so rugged or will have 
as good a chance of surviving. What a difference a too 
small amount of protein in the food of a growing animal 
will have on the tissues and health of the adult has been 
shown by W. A. Henry, of the Wisconsin Experiment 
Station. 

It had been noticed that pigs that were fed on a diet 
rather low in protein readily succumbed to disease. They 



220 



INFANT FEEDING. 



were very fat, but when slaughtered yielded a relatively 
small amount of lean meat or muscular tissue. To de- 
termine the effect of rich and poor protein diet on the 
bones and tissues Henry and others made some extended 
experiments. A number of healthy young pigs were 
selected ; part were reared on a diet low in protein and 
the others on a diet high in protein. At maturity both 
lots were slaughtered and their bodies analyzed. 

. The following figures from Henry will give an idea of 
the immense advantage to a growing animal of a diet 
high in protein. After an animal has matured there is 
no such advantage. 



Blood per ioo pounds weight : 

High protein diet 51.2 ounces. 

Low protein diet 36. 8 " 

Liver per 100 pounds weight : 

High protein diet 48.4 ounces. 

Low protein diet 31.9 " 

Muscular tissue : 

One third more on high protein diet. 
Strength of bone : 

High protein diet. Thigh bone broke at 503 pounds pressure. 

Low protein diet. Thigh bone broke at 3S0 pounds pressure. 




Fig. 60. —Fed Low Proteids. Ve 
(Carlyle.) 
Figs. 60 and 61 show Character of Flesh 



Fig. 61.— Fed High Proteids. Very Mus 
cular. (Carlyle and Hopkins.) 
suiting from Feeding with Low and High Proteids. 



It will be seen that a food that causes gain in weight 
is not necessarily a good food for an infant. The scales 
are not a safe guide by themselves in judging of an in- 
fant's development. 



INGREDIENTS OF INFANT'S FOOD. 221 

It is right here that thinking in percentages, as advo- 
cated by Rotch, is of the greatest value. It enables any 
one readily to compare the nutritional value of a substi- 
tute food with that of human milk. There is nothing 
complicated about it. All that is necessary is to have a 
general idea of the composition and digestibility of vari- 
ous foods that are used in infant feeding. For instance, 
human milk contains nearly 2 per cent of protein, and 
cow's milk diluted three times about 1 per cent; it is evi- 
dent, therefore, that an infant that is getting this diluted 
milk will receive only about half as much tissue-building 
food as the infant that gets breast milk. If in the human 
milk there was about 4 per cent of fat and 7 per cent of 
sugar, the breast-fed infant would have an immense ad- 
vantage over the infant getting the cow's milk diluted three 
times, which would contain only about 1.3 per cent of fat 
and 1.3 per cent of sugar. In all probability the breast- 
fed infant would be gaining in weight and strength while 
the bottle-fed baby would be weak, puny, and losing in 
weight. Under the old haphazard methods of feeding it 
would have been thought that this baby could not thrive 
on fresh cow's milk and it would have been fed on some 
proprietary food or condensed milk, with possibly a 
prompt gain in weight as a result, for reasons that will be 
given later. Under modern methods of thinking it would 
be known at a glance that the great trouble with the 
diluted cow's milk lay in its not supplying enough heat 
and energy-producing food. It could not be expected 
that getting only one-half the quantity of protein and one- 
quarter of the quantity of heat-producing food found in 
breast milk the bottle-fed infant could thrive. In the 
proprietary foods and condensed milk, as usually prepared 



222 INFANT FEEDING. 

for the infant, there is a larger quantity of heat-producing 
food (sugar) than is used up, which enables the infant to 
lay on fat and not use the protein for fuel; the result is 
gain in weight. If sugar had been added to the diluted 
cow's milk, gain in weight would also have followed. 

129. The problem of infant feeding does not consist 
simply of supplying protein and heat-producing food, of 
which sugar is a good example. Fat of milk contains 
lecithin, which is an important constituent of the nervous 
system, so it is necessary to see that an infant's food con- 
tains an amount of milk fat equal to that found in human 
milk, particularly as cow's milk contains less lecithin than 
human milk. As stated in the previous chapter and in 
chapter IV., the curding of milk is for the purpose of de- 
veloping the digestive tract, so it is essential that the basis 
of an infant's food should be the milk of some other ani- 
mal, although there is no milk that is exactly like human 
milk in curding properties. Though other forms of 
protein will nourish an infant, they do not cause its di- 
gestive tract to develop naturally. 

Cow's milk, which must be the basis of an artificial 
infant-food, was intended to nourish a calf that grows 
much more rapidly than an infant, and therefore contains 
much more protein than human milk. This protein was 
also intended for digestion in the stomach and forms solid 
curds which cannot readily leave the stomach. In an in- 
fant digestion takes place principally in the intestine, and 
human milk is especially adapted for easily leaving the 
infant's stomach. In the calf and cow, digestion, which 
takes place principally in the stomach, is prolonged, so 
when cow's milk is put into the infant's stomach it is not 
to be wondered at that it slowly leaves the stomach, or 



INGREDIENTS OF INFANT'S FOOD. 223 

that curds are vomited or appear in the stools. This 
curd question has been before infant feeders ever since 
cow's milk began to be used for infant feeding, and prob- 
ably always will be. 

To reduce the quantity of protein in the infant's food 
and also to modify the character of the curd, milk is 
diluted with various substances which will be described 
later. This diluting reduces the fat and sugar and they 
must be added if the food is at all to approximate human 
milk in composition. 

In many methods of preparing infant's food it has 
been recommended that certain quantities of cream of 
assumed richness be mixed with milk to increase the fat, 
and the mixture then diluted ; for each infant a special 
formula had to be calculated which was burdensome, and 
besides cream is so inconstant in composition that no ac- 
curacy could be insured no matter how exactly the calcu- 
lations were made. If centrifugal cream (43) was used, 
the emulsion of the fat was destroyed and there was a 
separation of the proteids (45) ; if gravity cream was used, 
the cream might be nearly twice as rich or only one-half 
as rich as it was thought to be. Where one infant thrived 
on a formula, another that apparently needed the same 
food was completely upset by it when prepared from dif- 
ferent milks and creams. In one instance to which the 
author's attention was called, it was calculated that the 
infant was getting four per cent fat ; an assay showed nine 
per cent, which explained an attack of indigestion. Many 
of the unsatisfactory results that have followed the use of 
cream and milk mixtures might have been avoided and 
much simpler methods of preparing food used had there 



224 INFANT FEEDING. 

been a better general understanding of the nature and 
composition of milk and cream. 

130. It is widely believed that cow's milk contains fat 
4 per cent, proteids 4 per cent, sugar 4 per cent, and 
gravity cream fat 16 per cent, and about the same quantity 
of proteid and sugar as whole milk. Now it is known 
that milk may contain anywhere from 3 per cent to 5 per 
cent of fat, from 3 per cent to 4 per cent of proteids, and 
from 4 per cent to 7 per cent of sugar; and gravity cream 
as low as 10 per cent and as high as 28 per cent of fat, so 
it is not to be wondered at that widely differing results 
were obtained with mixtures made after the same formula 
but with different milks and creams (38). 

One of the reasons that condensed milk is so popular 
as an infant's food is the ease with which it can be pre- 
pared for the infant's bottle; simply mix so much con- 
densed milk and so much diluent. Any quantity can be 
made up ; enough for one feeding or for all day. Now it 
is almost as easy to prepare from fresh cow's milk a food 
containing the quantities of fat, proteids, and sugar that 
are within the range of those found in human milk by the 
method about to be described. 

131. In human milk there is from two to three times 
as much fat as proteid. In cow's milk the quantities of 
fat and proteid are about equal. If cow's milk is allowed 
to stand for any length of time, the fat, being lighter than 
the other ingredients of the milk serum, will rise to the 
surface as cream. Whereas before the cream rose the 
quantity of fat and proteid in the milk was uniform 
throughout the entire quantity of milk, it is now apparent 
that in the upper creamy portion there will be many more 



INGREDIENTS OF INFANT'S FOOD. 225 

times as much fat as proteid. If in this upper milk there 
can be found a quantity which will uniformly contain be- 
tween two and three times as much fat as proteid, prepar- 
ing the infant's food will be a simple matter, requiring 
only the removal of this quantity from the top, diluting it, 
and adding sugar. By the use of bottled milk such a 
method can be carried out anywhere with the greatest 
ease and with the best results. Before describing the 
method in detail an explanation of the advantages and 
composition of bottled milk will be given. 

132. It has been shown that the bacteria which get 
into milk do not grow to any extent if the temperature is 
below 50 F. (60, 65), and that cream rises rapidly if the 
milk is quickly cooled to. below this point immediately 
after milking (41). If as soon as possible after milking the 
mixed milk of several cows is bottled and kept cool, the 
low temperature will retard the growth of bacteria and 
cause the cream to rise ; thus when this milk is delivered 
to families it will be fairly free from bacterial change and 
in condition to use at once in preparing the infant's food, 
and will not vary much in composition from day to day. 

It is a remarkable fact that in bottled milk there is 
generally about the same quantity of cream no matter 
how rich the original milk was ; but the richness of the 
cream varies greatly. One day the author had purchased 
nine quarts of bottled milk on which the cream had risen. 
When set in a row there was hardly any perceptible dif- 
ference in the depth of the layer of cream in any of the 
bottles. 

The milk and cream were then tested for fat. The 

poorest milk contained 3.1 per cent fat and the richest 
15 



226 INFANT FEEDING. 

4.6 per cent. The poorest cream contained 1 1.2 per cent 
fat and the richest 23 per cent. At other times creams 
poorer and richer in fat were obtained. 

The range of composition of whole milk before and 
after the cream has risen can be seen by a glance at the 
following illustration: 

QUART BOTTLE OF MILK QUART BOTTLE OF MILK 
BEFORE CREAM HAS RISEN AFTER CREAM HAS RISEN_ 




GRAVITY CREAM 

CONTAINS 10r< TO 24* FAT 



FAT AND PROTEIDS ARE 

NEARLY EQUAL EXCEPT IN 

VERY RICH MILKS 




REMAINING MILK 

OR 

SKIM MILK 

FAT .5* TO 1.5^ 

PROTEIDS 3^T0 4;« 
SUGAR 4f. TO 6* 




Figs. 62. and 63. 



-Milk Before and After Cream has Risen. 



The richness of the cream in fat depends a great deal 
on the size of the fat globules. In milks poor in fat the 
globules are very small (36) and rise slowly, hence cream 



INGREDIENTS OF INFANT'S FOOD. 



227 



from such milk is thin and bulky. In milks rich in fat the 
globules are larger and have greater buoyancy, hence they 
rise quickly and with some force. Cream from such milk 
is very dense near the top. For these reasons the layer of 



ONE QUART MILK 

4.1% FAT 

WITH CREAM RISEN 




LAYER OF CREAM 

NOT UNIFORM IN 
COMPOSITION 



LAYERS OF CREAM NOT UNIFORM 
IN COMPOSITION. 



FAT IN EACH OUNCE. 




I gIPZ. CONTAINS 25$ FAT 



23$ 



FAT IN DIFFERENT PORTIONS 

REMOVED FROM THE TOP 

AND MIXED. 



TOP 2 OZS. MIXED 24 f FAT 



19 $ " 


" 3 OZS. " 


22.5$ " 


18.5$ « 


" 4 OZS. '« 


21.4$ " 


10-.6* " 


" 5 OZS. " 


19.2$" 


4.8$ " 


" 6 OZS. " 


16.8$" 


3.4$ " 
2.2$ " 
1.8$ " 

1.2$ " 


" 7 OZS. •' 
" 8 OZS. " 
" 9 OZS. " 
" 10 OZS. " 


15.0$" 
13.3$" 
11.5$ " 
10.5$ " 


1.2$ " 


rt 12 OZS. " 


9.0$" 


1.2$ " 


" 14 OZS. " 


7.8$" 


1.2$ " 


" 16 OZS. " 


7.0$" 


1.2$ " 


" 18 OZS. " 


6.3$" 


1.2$ " 


" 20 OZS. " 


5.8$ " 


I.2K " 


" 22 OZS. " 


5.4$" 


1.2$, " 


" 24 OZS. •' 


5.0$ " 


1.2$ " 


" 26 OZS. " 


4.7$ " 


1.2$ " 


" 28 OZS. " 


4.5$ ««• 


1.2$ " 


" 30 OZS. " 


4.3$ " 


1.2$ " 


ALL MIXED 


4.1$ " 



Fig. 64.— Showing Distribution of Fat in Bottled Milk After Cr 



cream in the bottles is not at all uniform in composition, 

it being sometimes two or three times as rich in fat near 

the surface as near the junction with the remaining milk. 

The illustration above shows how the fat varies in 



22 8 INFANT FEEDING. 

different portions of the creamy layer. This milk had 
been passed through a centrifugal machine to remove 
dirt, and hence there was not so complete a separation of 
fat (42) as would have taken place in natural milk, as 
shown by the high percentage of fat in the skimmed milk, 
which is not usual. 

The table at the right of the bottle shows the composi- 
tion of different quantities of the cream when mixed; also 
of mixtures of all the cream aH. varying quantities of the 
remaining milk. It will be noticed that every ounce of 
remaining milk that is added to the cream reduces the 
quantity of fat in the mixture and that a great many mixt- 
ures, each containing a different quantity of fat, can be 
had from one bottle of milk. Glancing along this table 
it will be seen that the top nine ounces contain 11.5 per 
cent of fat, or about three times that of the whole milk, 
and the top 16 ounces 7 per cent, or nearly two times that 
of whole milk. These proportions hold good with any 
milk rich or poor, but the percentages of fat will vary, as 
shown by the following assays of poor, medium, and rich 
milk: 







Fat— per cent. 




Whole milk 


3-1 


4.2 


4.8 




13-4 

11. 6 

10.2 

9.2 

8.4 

7-7 

7-i 

6.6 

6.2 

5.8 

5-5 

• 7 


IQ.O 
16.4 
14.I 
12.6 

11. 4 
10.4 
9.6 
9.0 
8.3 
7-8 
7-4 
.6 


23.0 




19.8 




17-3 


" 9 " 


15.5 
13-9 


t< TI <i 


12.7 


,, ,, 


11. 7 


. l ~ l< 


10.8 




10.0 




9-4 




9.0 




• 4 








INGREDIENTS OF INFANT'S FOOD. 229 

Milk poor in fat yields top milk poor in fat. Milk 
rich in fat yields top milk rich in fat. This does not 
complicate matters; as rich milk is diluted more than 
poor milk, so rich top milk is to be diluted more than 
poor top milk. 

The next step is to see what separation takes place in 
the proteids and sugar, or solids not fat, of the milk, as the 
cream rises. For this purpose two quarts of milk were 
taken ; one was milk obtained from a milkman and then 
bottled and tested after having stood four hours for the 
cream to rise ; the other was a quart bottled by the milkman 
and delivered in the usual way, the cream having risen. 

The top nine ounces were removed from each -bottle 
and tested for fat and solids not fat (sugar and proteids) 
by the methods described in the section on milk testing 
(Chap. XIV.). It was found that there was only a slight 
falling off in the quantity of proteids and sugar in the top 
milks, as will be seen in the illustration (Fig. 65). 

It will be noticed that the cream did not separate 
completely in the milk that was obtained from the milk- 
man and stood in the bottle but four hours. This was 
because i't was not bottled immediately after milking. 
Cream rises quite completely in four hours if the milk is 
bottled shortly after milking, but not otherwise. 

From these illustrations it will be seen that it is hope- 
less to expect any degree of accuracy in making up food 
mixtures of milk and cream unless each is assayed, or 
to have the food uniform from day to day; but if definite 
quantities are removed from the top of a quart bottle of 
milk after the cream has risen, nearly the same composi- 
tion will be obtained each day, as a milkman's milk usu- 



230 



INFANT FEEDING. 



ally is quite uniform from day to day, and the strength of 
the food can be varied with the greatest ease by increasing 
or decreasing the dilution of the top milk. Any desired 
proportion between fat and proteids can be had by taking 




BOTTLED 
4 HOURS 

FIRST TEST 

FAT IN WHOLE MILK 
3.4* 



TOP 9 OZS. 
REMOVED AND MIXED 
/> CONTAINED 
FAT 8 

SOLIDS NOT FAT 6.6* 



REMAINING MILK 

OR SKIM MILK 

CONTAINED 

FAT 1.6 

SOLIDS NOT FAT 7.17; 



BOTTLED 
18 HOURS 

SECOND TEST 

FAT IN WHOLE MILK 
4.6* 



TOP 9 OZS. 
REMOVED AND MIXED 

CONTAINED 
FAT 14* 

SOLIDS NOT FAT 8.5<6 



REMAINING MILK 

OR SKIM MILK 

CONTAINED 

FAT .8* 

SOLIDS NOT FAT 8.76* 



Fig. 65.— Showing Solids not Fat in Top Milk and Remaining Milk. 

a greater or less quantity from the bottle. By varying the 
richness of the top milk in cream, and the dilution, the 
composition of the food can be varied to suit the infant's 
digestion. It should be remembered that percentages 
should be calculated after something that agrees with the 



INGREDIENTS OF INFANT'S FOOD. 231 

infant has been found ; it is then time to see if the food 
contains enough proper nourishment. This method al- 
lows the greatest variation in composition of food without 
any calculation, and when a food that suits the infant's 
digestion is found its composition can be known within a 
slight fraction, especially the protein, which is of such 
importance. 

These top milks should be looked upon as concen- 
trated milks that require dilution to suit the infant's diges- 
tion. Of course sugar must be added. About five or six 
per cent is the usual quantity required. This would be 
about one ounce of sugar to twenty ounces of food, or 
one-twentieth of any mixture (128). 

An easy way of bringing to mind the percentages ob- 
tained by various layers of milk may be acquired by tabu- 
lating the ingredients of 9 and 16 ounce top milk. It is 



Fat. 
Per cent. 


Proteids. 
Per cent. 


J 5 


4 


9 


4 


12 
8 


4 
4 


9 
6 


3 
3 



Sugar. 
Per cent. 



Very rich milk. Butter fat, five 
per cent. High grade, blooded 

Guernseys and Jerseys 

Rich milk. Butter fat, four per 
cent. Ordinary Guernseys and 
Jerseys 

Thin milk. Butter fat, three per 
cent. Holstein and ordinary 
milk cows 



9 ounces. 
6 ounces. 



(. To P 
) Top 

Top 9 ounces. 
Top 16 ounces. 

/ Top 9 ounces. 
i Top 16 ounces. 



based upon the fact that proteids in whole milk approxi- 
mate the fats up to 4 per cent. In actual practice milk 
varying from 3 to 5 per cent butter fat will be met. If 
the milk contains 3 per cent fat, it will have about 3 per 
cent proteids; 4 per cent fat, 4 per cent proteids, but 5 
per cent fat in milk is accompanied by only about 4 per 



232 



INFANT FEEDING. 



cent proteids. While the butter fat in milk can be de- 
termined only by assay (75)> certain grades of cows give a 
fairly uniform milk in this respect. 

It will be noticed that the top 9 ounces give a ratio of 
fats to proteids of 3 to 1, and the top 16 ounces a ratio of 
2 to 1, whether the milk is rich or thin. Hence practically 
the same percentages will be obtained by this method no 
matter what kind of milk is used. Rich milk will be 
diluted more and poor milk less to preserve the proper 
proportions. It is thus merely a matter of dilution, when 
we know the general strength of the whole milk. To find 
the percentages actually given to the baby, divide any of 
the above figures by the dilution. Thus, one part of top 
milk to three parts of diluent will give a dilution of 4. 

Kxample : g oz . xo P Miik. 16 oz. t op mhu. 

Fat. Proteids. Sugar. Fat. Proteids. Sugar. 

Very rich milk 4 )j_5 4 4 4)j? 4 4 

334 11 2% 1 1 

Rich milk 4)^ 4 4 4)^ 4 4 

311 211 

To get about the same percentages from thin milk 
use one part of top milk to two parts of dilutent, giving a 
dilution of 3. 

Fat. Proteids. Sugar. Fat. Proteids. Sugar. 

Thin milk 3 )g 4 4_ 3 ) 6 3 4 

311^ 211^ 

We can thus, by varying the dilution in a sliding scale, 
get a wide variation in percentages. In cases of indiges- 
tion it is simply a question of dilution, according to 
. whether the fats or proteids are disagreeing. If we wish 
to run down the fats, dilute a thin top milk, or even whole 
milk. If we wish to keep the fats high, dilute a rich top 



INGREDIENTS OF INFANT'S FOOD 233 

milk. A glance at the table will suggest many possible 
variations. The proper strength of the food must depend 
upon the digestive power as shown by the stools. In 
diluting cow's milk, the top pint of a quart of milk when 
creaming has taken place, even if simply poured off, con- 
tains a ratio of fats to proteids of about 2 to 1. In dilut- 
ing whole cow's milk, it is only necessary to remember 
that the fats and proteids are about equal in thin and 
moderately rich milk, the former containing fats and pro- 
teids 3 per cent, the latter fats and proteids 4 per cent. 
Both grades contain sugar about 4 per cent. 

The Principle of Top Milks. 

For top milk modification bottled milk is almost a 
necessity. As noted before, if milk is placed in the usual 
quart milk bottles shortly after milking and kept cool, the 
cream will rise rapidly, and within four or five hours prac- 
tically all will have risen, leaving only a fraction of one 
per cent of fat in the milk under the cream. When such 
instructions as to the care of the milk are given to the 
milk producer, the growth of bacteria in the milk will be 
retarded, and when the milk is delivered to the consumer 
not only will the cream be risen, but the milk will be in 
much better condition from a sanitary standpoint than if 
shipped in cans, which are not so easily and quickly cooled. 
The milk in bottles will not be opened in transit, and the 
danger of infection by the hands of drivers, by dust, or 
flies, is greatly lessened. The top milk method thus in- 
sures a fresher and safer food than when bulk milk is 
bought and allowed to stand for the cream to rise. 



234 INFANT FEEDING. 

The principles on which the percentage modification 
by the top milk method are based are very simple, and 
are as follows: The fat of the milk being lighter than the 
serum rises to the top as cream. The proteids and sugar 
remain distributed throughout the milk, but are slightly 
less in the very rich cream of the upper layers. There are 
from five to seven ounces of cream on a quart of milk. If 
this cream is all removed along with enough of the re- 
maining milk to make sixteen ounces, there will be two 
pints of milk, one containing nearly all of the fat of a 
quart of milk, and the other pint being practically fat free. 
It is self-evident that the percentage of fat in the pint con- 
taining all of the fat of a quart, or two pints of the milk, 
will be twice that of the original quart. If this was four 
per cent there would be eight per cent in the top milk. 
If all of the fat were in the upper third of a quart of milk 
the percentage would be three times four per cent, or 
twelve per cent. In practice all of the fat does not rise in 
the cream, so this ratio does not hold good exactly in 
practice: again, as milk does not run absolutely constant 
in fat percentage, another slight margin of error must be 
allowed for. If one works on a basis of four per cent milk 
the error will always be only a little above or a little below 
the calculated percentage. Theoretically four per cent 
milk will give the following strength of top milk: 

Whole Milk Top 20 Ounces. Top 16 Ounces Top 9 Ounces. 

Percent. Percent. Percent. Percent. 

4 6 8 12 

For several years the milk at the babies' wards of 
the Post-graduate Hospital has been assayed to deter- 
mine the strength of top milks, and below are the aver- 
age assays : 



INGREDIENTS OF INFANT'S FOOD. 235 

Top Top Top 

Whole Milk. 20 Ounces. 16 Ounces. 9 Ounces. 

Per cent. Per cent. Per cent. Per cent, 

I9°3 4-4 6.5 8.4 13.9 

1904 4.5 — 8.0 12.4. 

i9o"S- •• •" 4-8 6.5 8.5 13. 1 

These figures represent the average results obtained 
from 676 separate assays made during the three years 
mentioned. It will be seen that the percentage of fat in 
the top twenty ounces is almost exactly one and one-half 
times that of the whole milk; in the top sixteen ounces a 
little less than twice ; in the top nine ounces almost exactly 
three times that of the original milk. It is thus seen that 
this large number of actual assays approaches very closely 
in strength what would be .theoretically figured on in the 
top milks. When these milks are diluted to reduce the 
quantity of proteids the error of fat will seldom be greater 
than one-quarter of one per cent, which is negligible. No 
such certainty can be depended upon when part of the 
cream is removed and mixed with milk, or when cream 
obtained separately from the milk is employed. 

The top milk method thus means the taking of defi- 
nite quantities from the upper portion of a quart of milk 
after creaming has taken place and which shall include all 
of the cream and a certain portion of the under milk. In 
addition to the accuracy of this method, the natural emul- 
sion is not destroyed, and there is no combining of creams 
and milks of possibly different ages. Any desired layer 
of cream and milk can be easily removed by the author's 
cream dipper holding just one ounce. For purposes of 
ready calculation, we may consider the proteids as running 
very nearly equal to the butter fat in the whole milk up to 
four per cent. In the top nine ounces the ratio of fats to 



236 INFANT FEEDING. 

proteids will be about three to one ; in the top sixteen 
ounces, two to one ; in the top twenty ounces, one and 
one-half to one. 

J 33- Diluents. — There has been a great deal of discus- 
sion as to what diluent should be used. Jacobi has advo- 
cated for years the use of cereal waters on account of their 
rendering the curds of cow's milk softer; objection has 
been raised to this method on the ground that nature was 
not being followed, as no human breast secreted cereals. 
This argument is offset by the fact that no human breast 
has been known to secrete cow's milk, which was intended 
for so different a digestive tract (Chaps. IV., VI IE). 

No diluent has been proposed that does not have some 
effect on the curding of cow's milk. There is no denial of 
the efficacy of the cereal waters, but their opponents claim 
that they get as good results with plain water in most 
cases. It will be noticed that lime water is always to be 
added when plain water is used. This is stated to be for 
the purpose of rendering the milk alkaline. It was 
formerly thought that cow's milk was acid and that 
breast milk was alkaline in reaction, and that in modi- 
fying cow's milk to imitate breast milk some alkali should 
be added; lime water, bicarbonate of sodium, and carbo- 
nate of potassium have been recommended for this pur- 
pose. If cow's milk was really acid, as the term acid is 
generally understood, the addition of sodium bicarbonate 
should cause an effervescence of carbonic acid gas, which 
is not the case, for the addition of weak acids to fresh milk 
containing sodium bicarbonate causes a brisk efferves- 
cence of gas which shows that the milk had not decom- 
posed the soda. By careful examinations of breast milk 



INGREDIENTS OF INFANT'S FOOD. 237 

arid cow's milk it has been found that both will take con- 
siderable quantities of lime water to render them alkaline 
to phenolphthalein. Breast milk, requires 8 to 24 per 
cent, and the very best cow's milk 50 to 95 per cent. It 
is thought that it is the mucin of the milk that neutralizes 
the lime water, as the milk swells up and becomes viscid 
under the action of the lime. Swelling up in alkalies is 
peculiar to mucin. This effect is not noticeable when the 
sodium bicarbonate is added. The conception of acids 
and alkalies and the methods of detecting them have under- 
gone a great change within the past few years, with more 
knowledge of chemistry, and it is now known that litmus 
paper is a very unreliable, unscientific reagent to use in 
making comparisons of breast milk and cow's milk (82). 
The so-called radical difference between human milk and 
cow's milk of alkalinity and acidity has disappeared, and 
it is known that alkalies added to cow's milk prevent the 
stomach secretions from acting on the milk so as to form 
curds. In other words, the addition of alkalies to cow's 
milk for infant feeding has the effect of enabling the 
food to leave the stomach quickly and to pass into the 
intestines in a soft or fluid condition. The addition 
of alkalies to milk should be applied to the individual 
case as indicated and not necessarily be made a routine 
measure. 

Owing to the character of the curd of cow's milk, 
young infants cannot always take the quantity of protein 
that the breast-fed infant receives, which largely accounts 
for the well-known greater mortality of bottle-fed infants. 
It may be months before the bottle baby receives half as 
much cell-building material as the breast-fed. For this 



238 INFANT FEEDING. 

reason and others to be mentioned in another place (17) 
the author believes that the best general diluent for cow's 
milk is a cereal gruel in which the starch has been dex- 
trinized or rendered soluble by the action of diastase. 
This gruel, which may be made from any cereal, renders 
the curds of cow's milk more flocculent, and also increases 
the quantity of tissue-building protein the infant receives 
and digests, oftentimes by fifty to one hundred per cent, 
which is of great value. In the milks of all animals there 
is more or less soluble nutriment that can be absorbed 
without digestive effort, and particularly so in woman's 
milk. Diluting cow's milk, which contains less soluble 
nutriment than woman's milk, reduces the quickly absorb- 
able part of the food to almost nothing. This is partially 
replaced by the digested starch of dextrinized gruels, which 
is easily absorbed and assimilated. The youngest infant 
can usually assimilate these gruels, in fact in many cases 
there is no other form of nourishment so well borne. 
The advantages of this form of diluent are: (1) It acts 
mechanically on curds; (2) it furnishes tissue-building 
proteid in appreciable amount; (3) it forms the best tem- 
porary substitute for milk ; (4) it is always at hand when 
wanted; and (5) it can be easily and cheaply prepared (17). 

At the Pan-American Medical Congress of 1893 the au- 
thor proposed a method of preparing these gruels, which, 
however, proved to be too complicated for general use. 
Since then an easier process has been worked out. 

A simple decoction of diastase for dextrinizing gruels 
may be made as follows : 

A tablespoonful of malted barley grains crushed is put 
in a cup and enough cold water added to cover it, usually 



INGREDIENTS OF INFANT'S FOOD. 239 

two tablespoonfuls, as the malt quickly absorbs some of 
the water. This is prepared in the evening and placed in 
the refrigerator over night. In the morning the water, 
looking like thin tea, is removed by a spoon or strained 
off, and is ready for use. About a tablespoonful of this 
solution can be thus secured and is very active in diastase. 
It is sufficient to dextrinize a pint of gruel in ten or fifteen 
minutes. Such a decoction must be prepared each day 
as it soon spoils, owing to the unstable nature of the 
enzyme (11). For this reason it may be more convenient 
to use some commercial preparation of diastase. Of the 
many in the market the author uses and prefers a glycerite 
of diastase known as Cereo, which is specially made for 
dextrinizing gruels. This retains its activity indefinitely 
and under varying temperatures owing to the menstruum 
employed. 

Dextrinized or Digested Gruels. 

Much misapprehension exists as to dextrinized cereal 
gruels. Cereals, like all foods, contain fats, proteids, car- 
bohydrates, mineral matter, and water. The carbohy- 
drates are principally starch and a delicate cellulose or 
cell wall. Diastase dissolves starch and transforms it into 
a number of products depending largely on the conditions 
under which it acts. When cereals are boiled with water 
the starch grains swell up and rupture (Fig. 47), forming 
gelatinized starch or starch paste which is soluble in water 
to a very slight extent. This gelatinized starch forms an 
intensely blue color with tincture of iodine or with iodine 
test solution. 

When diastase is added to cereal gruels at a tempera- 



240 INFANT FEEDING, 

ture of about 150 F. the gelatinized starch passes into 
soluble starch, and the gruel thins rapidly. In a short 
time the soluble starch is transformed into dextrin* and 
partly into maltose. This transformation may be followed 
by testing with iodine a small drop of the gruel diluted 
with a test tube full of cold water, every two or three min- 
utes after the diastase has been added. The blue color 
gradually fades away as the starch is transformed. If it 
is desired to produce a very small quantity of maltose, the 
gruel may be boiled as soon as it is liquefied. The heat 
will destroy the diastase and prevent much action on the 
starch except liquefaction. In practical infant feeding 
no attention need be given to the particular products of 
the starch transformation, as they are the same as those 
that are produced in the livers of all animals which pro- 
duce glycogen. The youngest infant has such products in 
its circulation and readily assimilates digested gruels. 

When the starch of the gruel has been dissolved, there 
remain the coagulated proteids of the cereal and the deli- 
cate cell walls, cellulose, which are in a loose, flocculent 
condition, and which render the curds of cow's milk more 
porous. Dextrinized gruels containing as high as 3 per 
cent proteids, and 12 per cent soluble carbohydrates, may 
be made, and form an excellent diluent for milk for older 
children and adults in fever diets. These gruels not only 
render milk more digestible, but also have a favorable 
action on digestive secretion. 



INGREDIENTS OF INFANT'S FOOD. 241 

Standardized Gruels. 
134. From time immemorial cereal gruels have been 
used as a bland diet in fevers and in gastro-intestinal affec- 
tions, when milk and other more solid food was contrain- 
dicated. In more recent times, since the problem of arti- 
ficial infant feeding has forced itself to the front, gruels 
have been used to dilute cow's milk for infants because 
of their effect of softening the milk curds in the stomach 
and rendering the milk more digestible. 

The use of gruels for this purpose has been decried by 
some on theoretical grounds, it being claimed that it was 
unnatural, as human milk did not contain cereals. But it 
was just as apparent that human breasts did not secrete 
cow's milk ; and that as some substitute for breast milk 
had to be chosen, it was justifiable to use what gave good 
results. No one who has had experience with the use of 
cereal gruels in infant feeding will deny that marked im- 
provement often follows their use, and that they are the 
main reliance when milk must be temporarily discontin- 
ued. In spite of their well-known clinical value there has 
been a general impression that their use as a routine 
measure was unscientific. 

It has been taught that the proper way to modify cow's 
milk for infants was, in addition to diluting it and adding 
cream and sugar, to add a certain amount of alkali osten- 
sibly to overcome the acidity of the cow's milk. In prac- 
tice, however, enough alkali was often added to change 
the casein of the milk into a compound that would not 
form curds in the stomach, and very often more than 

enough to neutralize the action of the infant's gastric 
16 






242 INFANT FEEDING. 

secretions. The addition of alkali to milk really retards 
the process of gastric development, and often perverts it 
by throwing the entire work of digestion on the intestines. 
The effect of gruel diluents, on the contrary, is mechan- 
ically to soften the curds and thus allow the digestive 
tract to perform its function naturally. 

While it is well established that good clinical results 
often follow the addition of alkalies or antacids to cow's 
milk, it is going too far to lay it down as a general rule 
that the food of all infants should contain some alkali. 
When it is desired to prevent or retard the action of the 
gastric secretion on the milk, then an alkali is indicated ; 
but for the majority of infants it is desirable and proper 
to let the stomach perform its function and increase in 
digestive capacity. 

As the proteid of cow's milk is with difficulty digested 
by the infant, it must be reduced in quantity or modified 
in some way. When cow's milk is diluted with water 
sufficiently to reduce the amount of the proteid to suit 
the infant's digestive capacity, the quantity of proteid in 
the infant's food is often less than is needed to insure 
proper growth. It may be necessary then in modifying 
milk either to underfeed in tissue-building food (proteid), 
or interfere with gastric digestion by adding alkali, or me- 
chanically modify the curds by the use of cereal diluents. 
There can be no question as to which method is prefera- 
ble ; and therefore the writer has sought to establish ce- 
real feeding on a scientific basis. 

For the purpose of establishing some uniform standards 
the writer had made a number of different kinds of gruels 
and then had them assayed to determine their composi- 



INGREDIENTS OF INFANT'S FOOD. 243 

tion in order to show the relative proportion of tissue- 
building and heat and energy-producing elements. Pearl 
barley, prepared barley flour, wheat flour, and rolled or 
flaked oats, such as are sold in packages for family use, 
were used. The pearl barley was boiled for three hours 
in a saucepan and then strained, a portion remaining on 
the strainer. The rolled oats were cooked for one hour 
in a double boiler and then strained, a portion also re- 
maining on the strainer. The barley and wheat flours 
were cooked for one hour in a double boiler and strained, 
practically all of the flour passing through the strainer 
into the gruel. The gruels thus made were sent to the 
New York Agricultural Experiment Station where they 
were assayed by tie courtesy of the director, W. H. 
Jordan, and the following figures obtained: 

Plain Gruels. 

Total Proteid 

Solids. (NX6.25). 

1 oz. avoir, pearl barley to quart (32 oz.). • •• 1-483 per cent. 0.140 per cent. 
1 oz. avoir, prepared barley flour to quart 

(32 oz.) 2.28S " 0-195 

1 oz. avoir, wheat flour to quart (32 oz )... . 2.494 " 0-33 1 " 

1 oz. avoir, rolled oats to quart (32 oz.). . . . 1.931 " 0.262 

Dextrinized Gruels. 

6 oz. avoir, rolled oats to quart (32 oz.) 10.92 " 1.47 " 

6 oz. avoir, wheat flour to quart (32 oz.). .. . 15.12 " 1.81 

It will be noticed that the composition of the gruels 
made with six ounces of cereal to the quart is almost ex- 
actly six times the composition of the gruels made with 
one ounce to the quart. 

If an ounce of cereal is made up into a quart of gruel 
and none of the cereal is removed by straining, it is evi- 



244 INFANT FEEDING. 

dent that each ounce of the gruel will contain 3V ounce 
of the cereal and that the cereal has been diluted thirty- 
two times. From this illustration it is easy to see that if 
a definite weight of cereal is used in making the gruel, 
and none of it is removed by straining, the composition 
of any gruel can be readily calculated by dividing the 
composition of the cereal by the number of times it is 
diluted. This rule cannot be followed in the cases of 
cereals which are not completely broken up by cooking 
and part of which is removed by straining. However, 
it will be noticed in the assays of gruels made from 
rolled oats that practically the same proportion was re- 
moved in the gruel made with six ounces as in the gruel- 
made with one ounce of the oats, so this amount can be 
allowed for. 

To determine on a convenient and accurate method 
of obtaining different weights of the cereals, the writer 
had twelve different trained nurses measure them with a 
tablespoon made level full by sliding a knife along the 
edges, and also with the author's one-ounce cream clipper 
and the quantities weighed. Inquiry of one of the largest 
manufacturers of spoons in the country brought out the 
fact that there is no accepted standard of size for table- 
spoons used, and that they vary slightly in capacity, al- 
though all makers kept close to one size. 
It may be safely accepted, however, that 

level tablespoonful of pearl barley weighs ^ oz. avoirdupois. 

" barley flour % 

" wheat flour % 

" rolled oats " % 

ounce dipper ,: pearl barley V\ " 

" barley flour j4 

" wheat flour )4 

" rolled oats " . l A 



INGREDIENTS OF INFANT'S FOOD. 245 

A sixteen-ounce graduate of wheat flour weighs eight 
ounces avoirdupois, and the same measure of rolled oats 
weighs five ounces. 

From these observations it is possible to construct a 
simple table for use in making gruels of any desired 
strength. Of course this table will not be absolutely ac- 
curate because the composition of cereals is not always 
uniform ; and again, as the concentration of the gruels 
becomes greater, the increased specific gravity will slightly 
disarrange the calculated percentage composition. How- 
ever, this table will be as accurate as the tables used in 
modifying cow's milk for infant feeding. The percentage 
methods of feeding as emphasized by Rotch are an ad- 
vance in as far as they teach us to scrutinize food values. 
But the danger is of pushing the principle to an extreme 
that is liable to discredit the whole system, for undoubt- 
edly many results that have been attributed to fine per- 
centages have been due to other causes. It has been 
found that calculated milk food mixtures which gave good 
results, when analyzed, did not have the calculated com- 
position ; and it is not to be reasonably expected that it 
could be otherwise, for exact results cannot be obtained 
unless each specimen of the milk is chemically analyzed, 
which is out of the question as some of the analytical 
processes are extremely complicated and laborious. In 
addition, extended experiments on animals, where perfect 
control was obtained, have shown that mathematical 
accuracy in composition of feeding mixtures cannot be 
made the basis of successful feeding. In considering 
cereal gruels in this table the only divisions made are 
proteids and carbohydrates. Cereals contain only small 



246 



INFANT FEEDING. 



quantities of fat and mineral matter, and when made up 
into gruels the quantity of these elements actually pres- 
ent is so small as not to warrant their separate consider- 
ation on a percentage basis. 

Approximate Percentage Composition of Gruels made from 
Ordinary Cereals. 

TABLE I. 







Pearl 


Barley 


Wheat 


Rolled 






Barley. 


Flour. 


Flour. 


Oats. 




ui 








tfi 


IA 


in 


«; 






'5 





"0 


6jG 


3 
'53 



5$ 


"v 


£ 


6£ 

■eg 


1 ounce tc 


quart. . . 


0.14 


i-34 


I9S 


2.O93 


0.33I 


2. l6l 


0.262 


I.669 


2 ounces to quart. . 


.28 


2.68 


390 


4.186 


.662 


4.322 


• 524 


3-33* 


3 


' 






S8S 


6.279 


•993 


6.483 


.786 


S 


007 


4 








7«o 


8.372 


1-3^4 


8.644 


1.048 


6 


676 


5 " 


' " . . 






975 |i° 465 


1-655 


IO.805 


1. 310 


8 


345 


6 " 


' " 




1 


170 10.558 


1.986 


I 2 . 966 


1-572 


10 


014 


7 " 


' " . . 




.... 1 


365|i4-65i 


2-317 


15 127 


1.834 


11 


683 


8 " 






.... 1 


560 16.744 


2.648 


17.288 


2.096 


13-352 



Plain gruels cannot be made much stronger than two ounces to the quart. 
Dextrinized gruels may be made up to as high as eight ounces to the quart. 

Approximate Composition of Gruels made from Standardized Flours 
TABLE II. 





Barley. 


Legume. 


Oat. 


Wheat. 




jo 
'S3 




12 



6| 


IS 

ex 


8 " 


jo 
'53 

2 

Ph 


•eg 


i Level tablespoonful flour (H oz.) to 
quart of gruel 

2 Level tablespoonfuls flour (H oz.) 

to quart of gruel 

3 Level tablespoonfuls flour (% oz.) 

to quart of gruel 

1 Level coverful flour (1 oz. to quart 

of gruel 

2 Level coverfuls flour (2 oz.) to 











I2}S 

24 

36 
48 
96 




2 

4 
7 
9 


6o# 
20 
80 
40 
80 
20 
60 






2 
3 


19^ 
39 

S8 
78 
56 
34 


O 

2 

1 

6 

R 


53* 
06 
59 

12 

24 
36 

1« 










12?! 

24 

36 

48 
96 

44 




I 

4 

7 


603! 
20 
80 
40 
80 
20 
fin 








1 


IOJ! 

20 
30 
40 
80 
20 
6n 




1 

2 
s 


62^ 

25 

88 
SO 


3 Level coverfuls flour (3 oz.) to 




4 Level coverfuls flour (4 oz.) to 





































Since this work was done a series of flours for making 



INGREDIENTS OF INFANT'S FOOD. 247 

gruels, known as " Cereo-gruel Flours," has been put on 
the market. The cover of the package is used for measur- 
ing the flour, and on the label is given the composition of 
the grueis of different strengths. Great accuracy is thus 
possible in making gruels of any kind or strength from 
directions printed on the labels. (See Table II.) 

The high proteid gruels are of great value in many di- 
verse conditions. The author has employed them in per- 
sistent vomiting in patients of all ages; in the enfeebled 
digestive states accompanying typhoid and other fevers, 
and in general exhaustive conditions where the digestive 
and assimilative functions are at their lowest ebb. 

There is a widespread erroneous belief that vegetable 
proteids are not good tissue builders and are not readily 
digested. A moment's thought will show that they must 
be nutritious, for the greater part of the animal tissues of 
the entire earth are built up from vegetable proteids. All 
of the lean meat of beef, mutton, and pork is derived from 
vegetable proteids. The proteid of bread is vegetable, 
and it is almost entirely digested. Recent studies on 
the digestibility of bread, conducted under the super- 
vision of Atwater,* in which correction for metabolic 
products in the faeces was made, show that as high 
as ninety-eight per cent of the proteid of white bread 
is digested by men. 

Rockwood t has shown that the proteid of oatmeal is 
as thoroughly digested as meat, if it has been separated 

*" Studies on the Digestibility and Nutritive Value of Bread at the Maine 
Agricultural Experiment Station," 1899-1903. C. D. Woods and L. H. 
Merrill. 

f" The Utilization of Vegetable Proteids by the Animal Organism." E. 
W. Rockwood. Am. Jour. Physiol., 1904, No. 4. 



248 INFANT FEEDING. 

from the fibre. The reason cereal proteids are appar- 
ently indigestible is that they are enclosed in cellulose 
which prevents the action of the digestive fluids ; or the 
food is so coarse that it is hurried through the digestive 
tract and thus escapes the action of the digestive juices. 
Digestive experiments in vitro show the proteid of cereals 
to be easily digested if sufficient time is allowed. Cereals 
in the form of well-cooked gruels have the cellulose rup- 
tured, and so expose the proteids that they may be easily 
acted upon by the digestive enzymes. Edsall and Miller* 
have recently done some exhaustive work on the digesti- 
bility and metabolism of vegetable proteid in infants, and 
found that very often this form of proteid was utilized 
to better advantage than the proteid of milk. 

x 35- There are a certain number of cases that every 
physician meets in which cow's milk, even in the highest 
dilution, will not be tolerated temporarily. To some this 
is a source of mortification, especially when the mother 
tries some proprietary food with a prompt gain in weight 
as a result, after the doctor's efforts with cow's milk have 
failed. The trouble here is, the doctor has been trying to 
make the baby conform to his theory of what it ought to 
take instead of trying to find what it could take, and then 
adjusting the food as rapidly as possible so that it would 
contain enough protein to build cells, and enough fat and 
carbohydrates to produce heat and energy. 

In this class of cases condensed milk is often the best 
thing to start with, after being modified as described in 

""The Dietetic Use of Predigested Legume Flour, Particularly in Atro- 
phic Infants: with a Study of Absorption and Metabolism." By David L. 
Edsall, M.D.,and Caspar W. Miller, M.D. Am. Jour. Med. Sciences, 
April, 1905. 



INGREDIENTS OF INFANT'S FOOD. 249 

the following chapters. The great objection to condensed 
milk is not that it is condensed, but that the food ele- 
ments are out of proportion. 

136. In many cases in which the appetite is poor or 
digestion very weak, food is required that stimulates the 
appetite and flow of digestive juices, or that can be 
absorbed with little digestive effort. It is here that beef 
juice, scraped beef, broths, peptonized milk, whey, eggs, 
and gruels find their usefulness. 



CHAPTER XXII. 

PREPARATION OF FOOD. 

Top Milk Mixtures — Pasteurization — Percentage 
Composition — Whey and Cream Mixtures — Whey 
— Peptonized Milk — Scraped Beef — Beef Juice — 
Beef Tea — Meat Broths — Egg Mixtures — Milk 
Laboratories. 

137. In the previous chapters the character of the food 
required to develop the tissues and organs has been de- 
scribed and the methods of securing the raw materials. 
In this chapter will be given methods of preparing them 
for use of the infant under different conditions. 

For healthy infants top milk is diluted with water or 
gruel and sugar is added. Sometimes it is necessary to 
add lime water, bicarbonate of sodium, or citrate of sodium 
for specific purposes as will be explained later. 

The top milks can easily be removed by using the 
author's dipper* shown in the illustration. The first dip- 
perful must be removed with a teaspoon, as inserting the 
dipper into the full bottle will cause it to overflow. If a 
siphon is used to remove the milk from under the cream 
the sediment — there is always some — goes into the infant's 
food, and the manipulation is rather difficult. 

*Round-bottom aseptic dippers, known as the Chapin Cream Dipper, 
maybe had of Cereo Company, Tappan, N. Y., by mail for fifteen cents 
each. Aluminum dippers for twenty-five cents each. They may also be 
had through the wholesale druggists and from James T. Dougherty, 411 
West Fifty-ninth Street, New York. 



PREPARATION OF FOOD. 



251 



Since the introduction of the dipper in 1899 many have 
suggested that the bottom would push the cream down 
into the milk. This seems plausible, but a great many 




Figs. 66 and 67. — Quart Bottle of Milk Ready for Use, with Dipper. 



assays of the milk after the cream has been removed show 
that this is not the case. 

Diluents. — When obtainable it will be advantageous 
to use gruel flours (p. 247), one ounce of flour to a quart 
of gruel, but when these are not available beat up one to 
two heaping tablespoonfuls of barley, wheat, or rice flour 



252 INFANT FEEDING. 

with enough cold water to make a thin paste; or use two 
to four heaping tablespoonfuls of rolled oats. Pour on a 
quart of boiling water and boil for at least fifteen minutes, 
preferably in a double boiler as the gruel will not then 
burn. If the mixture is to be dextrinized after it is cooked, 
place the cooker in cold water, and when the gruel is cool 
enough to be tasted add one teaspoonful of diastase solu- 
tion or Cereo, and stir (133). This will thin the gruel. 
Strain, add salt to taste and enough boiled water to make 
a quart of gruel, and cool. 

Wheat, barley, and rice are well absorbed and should 
be used when the bowels move naturally. Oatmeal con- 
tains considerable coarse material that stimulates the 
bowels, and should be used when the bowels are consti- 
pated. 

Sugar is not added to sweeten the food, but to supply 
energy and heat-producing food. Two level tablespoon- 
fuls of granulated sugar weigh one ounce, and three level 
tablespoonfuls of milk sugar equal one ounce. 

It is best to write out for the mother or nurse the 
formula to be used in making up food and the intervals of 
feeding, somewhat as follows, the quantities and feeding 
intervals being about as suggested in the following table: 

Do not use one cow's milk. Get a quart bottle of good fresh 
mixed milk of a herd of cows from the dairyman, or if bottled 
milk cannot be obtained, place a quart of milk in a clean quart 
jar and set this on ice or in cold water until the cream has risen 
and appears as a layer at the top of the jar. This will take from 
four to six hours. When the cream has risen dip off the top . . . 
ounces ; that is, all the cream and enough of the remaining milk 
to make . . . ounces, into a clean pitcher or bowl. Take from the 



PREPARATION OF FOOD. 



253 



milk in the pitcher or bowl . . . ounces and add . . . ounces of [water, 
barley, oatmeal or wheat flour gruel] and . . . ounces of sugar. 
(A level tablespoonful is half an ounce.) Divide this into . . . 
feedings . . . ounces each, in separate nursing bottles, and plug the 
bottles with tightly twisted clean cotton. Do not use corks. 
Keep the food on ice or in as cool a place as possible. Feed . . . 
ounces every . . . hours. Warm the food by placing the bottle in 
warm water just before feeding. Do not keep food warm to avoid 
the trouble of heating it. The food may spoil. After the cotton 
stopper has been removed and the nipple adjusted, the food should 
drop slowly when the bottle is held upside down. 

Offer cool boiled water between feedings if the child appears 
hungry. If the food is not well digested, add one to two tea- 
spoonfuls of lime water to each bottle. In warm weather heat 
the food, as soon as made, for twenty minutes in a double boiler 
and cool before putting into the feeding bottles, or buy a pasteur- 
izer and pasteurize the food. Keep all utensils scrupulously clean 
and the nipples lying in a solution of borax when not in use. 



Age 
one to 

two 
weeks. 



Two 

to 

four 

weeks. 



Second 
month. 



Suggestive Table of Feedings. 

f Remove the top nine ounces from one quart of bottled milk into 
I a pitcher or bowl. Of this milk in the pitcher or bowl use four 
I dunces with fourteen ounces of water or dextrinized gruel and 
\ two level tablespoonfuls of sugar. 
Divide into nine feedings of two ounces each in separate nursing 
I bottles and feed every two hours during the day and twice at 
I night. 

f Remove the top nine ounces from one quart of bottled milk into 
a pitcher or bowl. Of this milk in the pitcher or bowl use seven 

j ounces with twenty ounces of water or dextrinized gruel and three 

' level tablespoonfuls of sugar. 
Divide iiito nine feedings of two to three ounces each in separate 
nursing bottles and feed every two hours during the day and 
twice at night. 

Remove the top eleven ounces from one quart of bottled milk 
into a pitcher or bowl. Of this milk in the pitcher or bowl use 
the entire eleven ounces with twenty-two ounces of water or gruel 
and four level tablespoonfuls of sugar. 

Divide into eight feedings of three to four ounces each in separate 
nursing bottles and feed every two and one-half hours during the 
day and once at night. 



254 



INFANT FEEDING. 



Third 
month. 



Four 

to 

six 

months. 



Seven 

to 

nine 

months. 



Ten 

to 
twelve 

months. 

Twelve 

to 
fourteen 
months. 



Remove the top sixteen ounces from one quart of bottled milk 
into a pitcher or bowl. Of this milk in the pitcher or bowl use 
fourteen ounces with eighteen ounces of water or gruel and four 
level tablespoonfuls of sugar. 
I Divide into seven feedings of four to five ounces each in separate 
| nursing bottles and feed every two and one-half to three hours 
I during the day and once at night. 

f Remove the top twenty ounces from one quart of bottled milk 
I into a pitcher or bowl. Of this top milk in the pitcher or bowl 
| use the entire quantity with sixteen ounces of water or gruel and 
-; four level tablespoonfuls of sugar. 

I Divide into six feedings of five to six ounces each in separate 
| nursing bottles and feed every three hours during the day and 
I once at night. 

\ Remove the top twenty-four ounces from each of two quarts of 
] bottled milk into a pitcher or bowl. Of this milk in the pitcher 
! or bowl use thirty-three ounces with fifteen ounces of water or 
gruel and four level tablespoonfuls of sugar. 

I Divide into six feedings of seven to eight ounces each in separate 
[nursing bottles and feed every three hours during the day. 

I Remove the top twenty-four ounces from each of tivo quart bottles 
J of milk into a pitcher or bowl. Of this milk in the pitcher or 
.j bowl use forty ounces with eight ounces of water or gruel and 
! four level tablespoonfuls of sugar. 

| Divide into five feedings of eight to ten ounces each in separate 
[nursing bottles and feed every three and one-half hours. 

j Whole milk, or. if not digested well, add one-fourth gruel. 
Amount in the bottle, from nine to twelve ounces. Chicken, 
mutton, or beef broths, in same amount, may also be given. 



138. After the food has been prepared it should be 
placed in separate nursing bottles and these plugged witr 





Fig. 68.— Nursing Bottle. 



Fig. 69.— Nursing Bottle, 
Preferable. 



Fig. 70.— Funnel for Filling 
Bottles. 



PREPARATION OF FOOD. 255 

clean cotton and kept on ice or in a refrigerator away from 
meat or vegetables, where the temperature is below 50 F. 
The temperature of many refrigerators is above 6o° F. and 
the milk should then be put in the ice receptacle. 

A self-registering maximum and minimum thermome- 
ter is kept in the refrigerator of the babies' wards of the 
New York Post Graduate Hospital, and during an entire 
year the temperature of the refrigerator did not fall below 
40 F. During the summer months the range of temper- 
ature was from 50 F. to 65 ° F. This refrigerator is un- 
doubtedly much better than those in ordinary use, so the 
necessity of having the food kept in the ice receptacle, or 
in cracked ice, will be apparent. When the temperature 
of the food is likely to rise above 6o° F., it is best to pas- 
teurize the food — heat to 155 to 165 F. 

The Freeman pasteurizer or Arnold sterilizer may be 
ased for this purpose ; or a pasteurizer may be made from 
a six-quart tin pail. A false bottom is made by punching 
holes in a tin pie plate, which is 
to be inverted in the pail ; this 
prevents the bottom of the bot- 
tles getting too hot. It is best 
to have a thermometer pass in- 
to the water through a cork fit- 
ted in a hole in, the cover. 

The bottles are placed in 

Fig. 71. — Freeman Pasteurizer. 

water up to the level of the milk 
and the water is heated up to 165 F. The pail is then 
removed from the heat and covered with a cloth and al- 
lowed to stand for half an hour. Where a thermometer 
cannot be had, the water should be brought nearly to the 




2 5 6 



INFANT FEEDING. 



boiling point before being removed from the heat. The 
bottles are then cooled by first being placed in luke-warm 
water and then in cold water. Pasteurized milk should 
be kept below 6o° F., or the spores in the milk will develop 
into active bacteria (48). A simple and practical method 
of keeping 
nursing bot- 
tles cool, sug- 
gested by De 
Forest, is to eggg 
place cracked wg 
ice around 
them in the 
pasteurizer; 
this saves possible infection from food in a refrigerator. 
A quart bottle of milk may be pasteurized without dis- 




Fig. 72-— Arnold Sterilizer 




Fig. 73. — Home-made P. 
(Russell 



asteurizer for Bottled Milk. 
(Russell.) 



turbing the cream by setting it in a kettle or pail and 
heating as just described. 



PREPARATION OF FOOD. 257 

Sterilizing (heating to 212 F.) is not employed so 
much as formerly, as the taste of the milk is greatly 
altered and certain chemical changes are also produced. 
There are no corresponding advantages that offset these 
objections (61). 

When conditions are such that pasteurization as de- 
scribed cannot be carried out, the milk may be brought to 
a boil, preferably in a double boiler, and then covered and 
allowed to stand for twenty minutes and then cooled. 

139. Pasteurization of Food. — When good fresh milk 
can be obtained, it is better not to pasteurize, as owing to 
the germicidal property of properly handled fresh milk 
little bacterial change will have taken place ; but when the 
milk is of doubtful quality and freshness, the infant's food 
should be pasteurized as soon as made up (138). If the 
milk reddened test paper, lime water, syrup of lime, or 
bicarbonate of soda (133) should be added to the food 
after pasteurization, until the reddened paper turns blue 
again. 

Pasteurization has several practical effects. In the 
first place it alters the milk so that it is not easily acted 
upon by the rennet of the stomach, and curded. Secondly, 
it destroys acid-producing bacteria, which promote the 
action of the rennet ferment in very dense curds. Conse- 
quently, when there is great difficulty with the digestion 
of curds of milk, pasteurization of food may prove to be 
beneficial. It must be remembered that ^/^pasteurized 
milk may prove to be very poisonous, so the food should be 
freshly prepared and pasteurized the day it is to be used. 
The natural enzymes of milk are destroyed at about 
158 F., but it is doubtful if they have any practical value 



258 INFANT FEEDING. 

as digestive aids, as it takes months for them to produce 
much change in the proteids of the milk outside of the 
digestive tract (3 2 B , 61). 

Special Modifications. 

140. If any of the above formulas disagree remedial 
measures as follows may be tried. If there is vomiting or 
spitting up shortly after feeding, the amount of fat in the 
food should be reduced by using weaker top milk, that is,, 
if the top nine ounces have been used, remove the top six- 
teen ounces or if necessary use whole milk temporarily in 
making up the food, otherwise following the directions. 
If there is vomiting, colic, and curdy stools, a tablespoon- 
ful of lime water may be added to each feeding, or a pinch 
of baking soda, or one or two grains of citrate of sodium. 
These additions chemically alter the proteids of the milk 
or retard the action of the gastric secretions on the milk 
so that curds are not formed as rapidly as when natural 
milk is acted upon by the natural secretions. 

141. Lime water added to the food often proves bene- 
ficial, especially when there is vomiting or when the milk 
is slightly acid to litmus paper. It may be obtained at a. 
drug store or readily prepared at home as follows: Get a 
lump of lime at a grocery store. Pour on a quart of water 
in an open vessel and allow it to slake. When this proc- 
ess is completed and the lime has settled, pour off the 
clear liquor at the top, as this contains the potash and 
soda and other soluble impurities in the lime. Stir up 
the lime with another quart of water and pour off as be- 
fore ; this will leave the lime quite pure. The lime may 



PREPARATION OF FOOD. 



259 




Fig. 75.— Baby Food 
Warmer. 



then be placed in a large bottle or quart fruit jar and this 
filled with water. When the lime water is clear it may 
be poured off into any convenient bottle for use, and 
more water poured on the lime. This may 
be repeated as long as any lime remains 
undissolved, but it is well to use a new 
lump of lime every two or three months. 
142. Before giving the infant its bottle, 
the food should be warmed by placing it 
in warm water. A very convenient " Baby 
Food Warmer" is shown in Fig. 75. The 
heater is an alcohol stove which will warm 
an eight-ounce feeding in from three to 
five' minutes. It is small enough to be 
carried when travelling. 

Remove the cotton stopper from the bottle and fit on 
the nipple. Pure rubber nipples should be used. These 
will easily stretch several inches and resume 
their original shape ; inferior nipples do not 
stretch easily. Invert the bottle and see 
that the hole in the nipple is large enough 
to allow the food to drop slowly, not run 
in a stream. Before feeding it is necessary 
to see that it is not too hot. A practical 
method of testing the warmth of food sug- 
gested by Marianna Wheeler consists in 
allowing a few drops to fall on the wrist. 
The nipple should never be put in the at- 
tendant's mouth. The infant should be held while nursing 
in as nearly the natural position as possible,' and should 
not be allowed over twenty minutes in which to take food. 




Nipple. 



260 



INFANT FEEDING. 



Regularity in feeding should be followed, and the hours 
at which feedings are to be given should be written down 
for the mother or nurse, as in breast feeding (114). Noth- 
ing but cooled boiled water should be offered between 
meals. It is well to remember that infants become thirsty. 
The infant should be weighed each week and a record 
kept of its weight (173). Unless there is a steady gain in 
weight something is wrong. If the infant 
shows no signs of discomfort or indigestion, 
use a stronger food — that is, more top milk 
and less diluent. If there is indigestion and 
colic, the food will have to be changed as 
described in another place (161). 

If the infant is restless at night or if one 
feeding is vomited, it is well to substitute a 
feeding of the diluent (133), which will give 
the digestive tract a rest and at the same time 
maintain the infant's strength. This is espe- 
cially beneficial in warm weather when the 
fig. 77. -Bottle digestive function is depressed. When an in- 
fant vomits rancid curds shortly after feeding, 
use weaker top milk ; that is, if nine-ounce top milk causes 
trouble, try sixteen-ounce top milk or even plain milk (132). 
This reduces the quantity of fat that becomes rancid in 
the infant's food. Sugar may also be reduced a half. 




Care of Nursery Utensils. 

143. — After the food has been made up or the nursing 
bottles have been used, the dipper, measures, bottles, and 
anything that has had milk in should be first rinsed with 



PREPARATION OF FOOD. 



261 



cold water, then washed with hot water and soap or some 
of the washing powders, and a bottle brush. If hot water 
is used first, the milk " cooks on " the utensils, and it is 
then difficult thoroughly to clean them. 

Cleanliness is a very important part of infant feeding, 
as dirty utensils may harbor bacteria (59) that cause de- 
composition in the food and hence produce sickness in 
the infant. After washing with hot water the utensils 
should be boiled and the bottles either kept filled 
with water or inverted in a clean place until wanted for 
filling. 

The nipples should be washed out and kept lying in a 
cup of water in 
which a pinch of 
borax or boric acid 
has been dissolved. 

To be sure of 
having a supply of 
boiling water, a 
gas stove or oil 
stove should be in 
every nursery out- 
fit. 

144. Pictorial di- 
rection blanks with 
table for changing 
ounces into per- 
centages and percentages into ounces have been devised 
by Deming from which the following extracts have 
been taken: 




Fig. 78.- Oil Stt 



262 



INFANT FEEDING. 




® • s\ 


2&b« 1 


6 

rm the fc 
htly and 
ottle eve 

timea at 




M- I" 1 


•0 


■o S j 




«, ISlc 










e. in,* 


£ 


I | 




Add 
ated 




Vllj 


IIieI 


M 


n 8 |2£3 1« 




6 1--: 




„ ? si S 

1 las! 


•o — .— 


■o" 






1 ; § 


| S o 


i o s 



f- J 



X I tut 



>1 1 



i? 



Sllhj^ 



5Z3 



II 



f ^miMiiiiL 

* 1 



1* ?2 

£5S 



,_ 


tin 


.3 - 


- 


- 




R 


— 


- n> 


















b/j 


g 


% 








bC 




"o 3 




















j,, 


&, 


"o 








ti 






= 


-5 


O fO 


\ 


o 




a. 




5 o 

U <L> 



H ~ 









M j< a +; 












B fc,S O . G* 








"o 


o 


- a c jo 


Vo, 


lt. q -t- 










wd 




3 




ffl So £ 








"S 




fcJ3 ^ O. *J 








£ 


lO 


By usin 
io per 

cent mil 

or the to 
II oz. 

from l q 


&? ^ ^ 












N l^lVO 









m in ro 


u-.vd t-^06 




£ 














c C I- - c 


E£ 






rO_0 




By usi 
7 per ce 
milk o 
the top 
oz. fro 
iqt. 






s"3 


Tj- 




io-*)- « 




£^ 






ro * i^i'O 




I'S 

o.S 










ro 


ig By using 
nt 6 per cent 
r milk or 
24 the top 20 
11 oz. from 
iqt. 


^) 


q n«n 


c 
< 

H 

•z 







£° 


f^ro4 w 


o 


M 




y usii 

per ce 
milk 
le top 
z. froi 
iqt. 






rt 








Pi 


C 




VO N 00 


10 O r~ T 

pi <^ <r> T 




u 




~xr, 33 




















a 




Sir u 








.£5 




% S °-|^ 


6? 






H 


M 


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LO V 


O u",0 10 








H M 


fi « "5W) 




























2 




%•%£*„ 


S5 











*%%<*& 





O TOO 






PREPARATION OF FOOD. 



263 



The following formulas are a condensation of the sug- 
gestive table of feedings on page 253: 



Age. 


Remove 

from one 

quart of 

milk. 


Use 

of 

this. 


Add boiled 

water or 
gruel (1 oz. 
flour to qt.) 


Sugar 
in level 
table- 
spoon- 
fuls. 


Number 
and size 
of feed- 
ings for 
24 hrs. 


Feeding 
Intervals. 


1-2 weeks 


Top 9 oz. 


4 oz. 


14 oz. 


2 


9-2 oz. 


2 hours 
Twice at night. 


2-4 weeks 


Top 9 oz. 


7 oz. 


20 oz. 


3 


9-2 to 
3 oz. 


2 hours 
Twice at night. 


2d month 


Top 11 oz. 


II oz. 


22 oz. 


4 


7-3 to 
4 oz. 


2}/2 hours 
Once at night. 


3d month 


Top 16 oz. 


14 oz. 


18 oz. 


4 


7-4 oz. 


2 l A to 3 hours 
Once at night. 


4th-6th month 


Top 20 oz. 


20 OZ. 


16 oz. 


4 


6-4 to 
6 oz. 


3 hours 
Once at night. 


7th~9th month 
ioth-i2th month 


1 Top 24 oz. J 
< from each V 
( of two q'ts ) 


33 OZ. 

40 oz. 


15 oz. 
8 oz. 


4 
4 


6-6 to 
8oz. 
5-8 to 
10 oz. 


3 hours 
During day. 

3%, hours. 
During day. 



See p. 264 for percentages of proteids and carbohydrates added by gruel. 



Approximate Composition of Mixtures. 



1-2 weeks 

2-4 " 

2d month 

3d month 

4th-6th month. . 
7th-oth month.. 
ioth-i2th month 



Fats. 


Carbo- 
hydrates. 


2-7% 


6.0% 


3° 


7.0 


3-° 


7.0 


3-o 


7.0 


3° 


7.0 


3-5 


7.0 


4.0 


7.0 



.80 

1.0 

1.4 

2.0 

2.2 
2.6 



145. For working directly with percentages an ingeni- 
ous device known as the Deming Percentage Milk Modifier 
may be used (Fig. 79). This is based on the use of differ- 
ent top milks. The percentages are placed on the glass so 
as to indicate the height to which milk must be poured to 
give the percentages after the diluent has been added. 
To make a mixture containing 1 per cent of proteids, milk 
is poured into the modifier up to the i-per-cent proteid 
mark and the diluent is added. If whole milk is used the 



264 



INFANT FEEDING. 



combination will be proteids 1 per cent, fat 1.2 per cent. 
If top sixteen ounces are used the percentage of fat will 

be 2.2 per cent, and if the top 



eleven ounces are taken the 
percentage of fat will be 3.1 
per cent, the percentage of 
proteids being 1 per cent. 
A prescription blank is used 
with the modifier, which is 
filled out by the physician 
and given to the mother or 
nurse. 

146. Thefollowingfigures 
show approximately the com- 
parative nutritive value of 
modifications of milk made 
with water diluent and gruel 
made from standardized gruel 




Fig. 79- — The Deming Percentage Milk 
Modifier. 



flours (p. 247), one ounce to quart: 





Proteids 


Carbohydrates 


Proportion of milk 


Water 
Diluent. 


Gruel 

Diluent 

1 oz. to qt. 


Water 
Diluent. 


Gruel 

Diluent 
1 oz. to qt. 


yi 


.40% 
.So 
1 . 20 

1 . 60 
2.00 

2 .40 


.80% 
I. 16 

I . so 

1. So 

2 . 20 
2 . 50 


.60% 
1 . 20 

1. So 

2 . 50 
3 -oo 
3-7o 


2-7% 
3° 
3-6 
3.8 


X 


y s 


y z 


3/ 8 


4.0 
4-3 


X 





It will be noticed that when low percentages of milk 
proteids must be used the gruel brings the percentage of 
proteids in the food nearly up to that found in human 



PREPARATION OF FOOD. 



>6 5 



milk, and undoubtedly accounts in part for the excellent 
results generally obtained when gruel diluents are used. 

Laboratory Feeding. — In a number of the larger cities 
are to be found the Walker-Gordon laboratories which are 
intended to be what might be called food pharmacies. 
They were established as the result of Rotch's teachings. 
The physician fills out either of the following prescription 
blanks and the laboratory attendants use the ingredients 
necessary to produce the desired percentages. 

The Walker-Gordon Laboratory. 



Per cent. 


Remarks. 


A Fat 

Milk sugar 

Albuminoids .... 




Number of 

feedings ? 

Amount at 

each feeding ? 








Total solids 

Wnfpr ...... 


Infant's weight ? 


IOO 


00 




For whom ordered. 
Date, 


Signature, 







If the physician does not care to mention the especial percentages, he can ask 
for percentages which will correspond to the analysis of average human milk, and 
he can then vary any or all of these percentages later, according to the need of the 
special infant prescribed for. 



A recognition of the wide utility of other diluents than 
mere water, and the specific action and purpose (133) 
of the addition of certain substances has called for a sup- 
plementary and more complete prescription blank. 



266 



INFANT FEEDING 



Fats ... . 

(a) Carbo-hydrates 

(b) Dextrlnlze . 



'Lactose (Milt Sugar) 
Mallwe (Malt Sugar) 
Sucroae (Cane Sugar) 
Dextrasel Grape Sugar) 
Starch .... 



(d) Peptonize 

(e) Sodium Citrate { | i^\ZiZT° 
(0 Sodium Bicarb, j $^{SslS- 
(g) Lime Water { IS^r". 



00 



Lactic Acid \ 



Bacillus 

Heat at 



t'\ 



Number of Feedings. 



Amount at each Feeding . 



ORDERED FOR 



EXPLANATORY 

(a) It requires .75% starch to make the precipitated 
casein finer. 

(b) One hour competely dextrinizes the Starch. 

(c) In case physicians do not wish to sub-divide 
the proteids, the words "Whey" and "Casein" may. 
be erased. 

(d) Twenty minutes renders the mixture decidedly 
bitter. 

(e) It requires 0.20% of the milk and cream used 
in modifying to facilitate the digestion of the proteids; 
I. e. the formation of a soft curd. 0.40% to prevent 
the action of rennet ; i. e. the formation of tough curd. 

(f) It requires .68% of the milk and cream used 
in modifying to favor the digestion of the proteids. 
1 .70% of the amount of milk and cream used suspends 
all action on the proteids in the stomach. .17% of 
the total mixture gives a mild alkaline food. 

(g) It requires 20% of the milk and cream used 
in modifying to favor the digestion of the proteids. 
50% of the amount of milk and cream used suspends 
all action on the proteids in the stomach. 5% of the 
total mixture gives a mild alkaline food. 

(h) Percentage figures represent the per cent, of 
Lactic Acid attained when the food is removed from 
the thermostat. When the Lactic Acid Bacillus is 
used to facilitate digestion of the proteids, this Is the 
final acidity, as the process is stopped by heat at this 
point. When the Lactic Acid Bacillus is used to in- 
hibit the growth of saphrophytes, the acidity may sub- 
sequently increase to a variable degree, as the bacilli 
are left alive. .25% Lactic Acid just curdles milk. 
.50% gives thick curdled milk. .75% separates into 
curds and whey. 

WALKER-GORDON LABORATORY CO. 

793 BOYLSTON STREET 
BOSTON 

And all Large CiUes 



Without a knowledge of dietetics a food laboratory is 
of little value to a physician, who must have a knowledge 
of percentages and other modifications required by various 
conditions to use this valuable agent intelligently. 

While the laboratories have much to commend them, 
the expense and unavailability put them beyond the reach 
of the great majority. 



CHAPTER XXIII. 

FOODS FOR DIFFICULT CASES AND FOR 
TEMPORARY USE. 

147. It is easy enough to prepare a substitute food that 
will contain as much nourishment as breast milk, but 
often such food causes digestive disturbance or fails to 
promote the normal development. Therefore substitute 
infant feeding calls for a careful study of each case to dis- 
cover if possible why the substitute food is not succeeding. 
Sometimes it will be found that there is a deficient flow 
of digestive juices; in such cases food that can be 
absorbed with little digestive effort is indicated. At other 
times the intestinal digestive juices will act, but the stom- 
ach is at fault ; here food that can easily leave the stom- 
ach is indicated. Again, there may be poor absorption. 

As any food that is not digested or absorbed will be 
found in the stools, an examination of an infant's stools 
will often show where the trouble lies, and is absolutely 
necessary if intelligent feeding is to be done, as food that 
would be indicated with one kind of stool might only 
aggravate the trouble if fed to an infant passing another 
kind. The napkins should also be examined to see if the 
urine leaves any stain, as a deposit of urates shows faulty 
metabolism. 



268 INFANT FEEDING. 

Infant's Stools. 

The normal infant stool is smooth, yellow, homoge- 
neous, and of about the consistency of thin mush. The 
following may be considered abnormal types : 

Curdy Stools. — Curdy lumps may consist of undi- 
gested casein or fat. The former are hard and yellowish, 
while the latter are soft and smooth, like butter. 

Green Stools. — Stools can be considered green only 
when that condition is evident immediately upon their 
passage. They are thought to be due to a fermentation, 
which is doubtless the result of bacterial action. Certain 
drugs also produce green stools (27). Stools often be- 
come green a certain time after passage, caused by oxida- 
tion of the air. 

Slimy or Mucous Stools. — These are the result of ca- 
tarrhal inflammation. When the mucus is mixed with 
the fecal matter, the irritation is high up in the bowel, 
but when flakes or masses of mucus are passed, the trou- 
ble is near the outlet. 

BJoody Stools. — The appearance of these stools will 
depend on the portion of the digestive tract that is affect- 
ed. Small masses of dark clotted blood mixed in with 
fecal matter indicate that the seat of hemorrhage is high 
up, usually in the small intestine. When bright-red 
blood is passed, the seat of hemorrhage is low down, usu- 
ally a little above the anal ring. Hard masses of casein 
may rupture the capillaries, or a fissure or polyp may be 
the cause of the bleeding. The appearance of fresh, 
bright-red blood in stools is more alarming than danger- 
ous. The presence of dark clotted blood is of graver sig- 
nificance. 



FOODS FOR DIFFICULT CASES. 269 

Yellow, Watery Stools. — These are seen in depressed 
nervous conditions, especially in the hot days of summer, 
when the bowel is relaxed and the inhibitory fibres of the 
splanchnic nerve do not act to advantage. 

Very Foul Stools. — These are caused by decomposi- 
tion of the albuminoid or proteid principles of the food 
(54). 

Profuse, Colorless, Watery Stools, with little fecal mat- 
ter, are doubtless caused by an infective germ, akin to 
that of Asiatic cholera. This condition is known as 
cholera infantum. The fluid consists largely of serum 
exuded from the blood-vessels, and the infant is quickly 
drained as if by a hemorrhage. This is often preceded 
by a few foul fecal stools. 

It is rare to see one of these types by itself. With 
the exception of the last, they may be seen in all combi- 
nations. 

Suggestions as to how the character of the food may 
be altered to suit the peculiarities of ordinarily healthy 
infants have been given in (137). The food mixtures 
given here are intended for use after those for healthy in- 
fants have failed to agree. In selecting a food formula 
for temporary use from the following, it should be remem- 
bered that fats in excess retard gastric secretion, and that 
too much sugar promotes the flow of an abnormally acid 
gastric juice. Therefore these ingredients should be re- 
duced in quantity when there is gastric disturbance. Ex- 
cessive vomiting may be due to mucus in the stomach, 
which may be removed by washing (165), or to nephritis. 

In all forms of fever fats should be reduced in quantity 
and easily assimilated carbohydrates in the form of dextri- 



2 7 o INFANT FEEDING. 

nized gruels (137) supplied along with milk, to reduce as 
much as possible the excessive destruction of protein tis- 
sues that takes place in fevers (13, 14? J 9> 2 5)- 

Foods for Cases that Fail to Thrive on Fresh 
Milk Modifications. 

148. A certain number of cases will be met which do not 
gain on any modification of fresh milk, but which promptly 
thrive when the food is cooked and the character of the 
carbohydrates is changed. The following mixtures may 
be tried when the symptoms do not indicate that all milk 
should be temporarily discontinued. If they agree with 
the patient they may be continued, but the patient should 
be watched to see that scurvy, which may be mistaken for 
rheumatism, does not intervene. It is a good plan to 
order orange juice or beef juice, one to two teaspoonfuls 
two to three times a day, with these cooked foods. 

Formula No. i. 

Whole milk 12 ounces. 

Wheat or oat ) level table nfuls . 

gruel flour > 

Granulated sugar 2 " 

Salt 1 pinch. 

Cold water 22 ounces. 

Mix all together cold and with constant stirring slowly bring to a boil and 
boil for three minutes. Strain and add enough boiled water to make thirty- 
two ounces. Feed quantity appropriate for age. For young infants or very 
delicate ones the food may be diluted with one part of water to two parts of 
the food. 

Approximate Composition. — Fat, 1.5 per cent.; carbohydrates 

, starch \ 

- milk sugar > 7 per cent.; proteids, 1.5 per cent. By using the top 16 

' cane sugar ) 

ounces from one quart of milk and taking 12 ounces of this instead of whole 
milk in the above mixture the percentages will be : Fat, 2.5 per cent. ; car- 
bohydrates, 7 per cent. ; and proteids, 1.5 per cent. 



FOODS FOR DIFFICULT CASFS 271 

Formula No. 2. 

Whole milk 12 ounces. 

Wheat or oat gruel flour 4 level tablespoonfuls 

Glycerite of diastase (cereo) 3 teaspoonfuls. 

Salt 1 pinch. 

Cold water 22 ounces. 

Mix all together cold and with constant stirring bring slowly to a boil and 
boil for five minutes. Strain and add enough boiled water to make 32 
ounces. Feed quantity appropriate for age, or dilute two parts of the food 
with one part of water for very young or delicate infants. 

Approximate Composition. — Fat, 1.5 per cent. ; carbohydrates 
r soluble starch"] 
dextrin I 

\ ma i tose r 6 P er cent ; proteids. 1.8 per cent. If top 16 ounce milk is 

i milk sugar 
used instead of whole milk the percentage of fat will be 2.5 per cent. 

With both of the above formulas it will be better to 
begin with whole milk and increase to top sixteen ounce 
milk if digestion is good. 

Keller's Malt Soup is a mixture similar to the above. 
It is made by boiling milk, water, wheat flour, and Loe- 
flund's Malt Soup Extract together. The carbohydrates 
in the mixture are starch, maltose, and milk sugar. 

Condensed Milk Mixtures. 

149- Occasionally infants will be met who cannot di- 
gest the casein of cow's milk without constant difficulty 
and distress. The shifting of percentages or altering the 
diluent appears to make little difference in these cases, as 
the infant continues to fret and to show a stationary or los- 
ing weight. This may be the culmination of many at- 
tacks of indigestion, or sometimes it seems to be sort of 
gouty or lithaemic heritage, perhaps coming directly from 
the parents, and showing itself in such a form at this 



272 INFANT FEEDING. 

early age. After a fair and intelligent trial of ordinary 
cow's milk has proved unsuccessful, it is best to put the 
infant on condensed milk. The process used in condens- 
ing appears to produce a change in the casein that make* 
ir easier of assimilation in this class of cases. Fresh con- 
densed milk is preferable, but when this cannot be ob- 
tained the best brands of sweetened condensed milk may 
be used. Sometimes it is necessary to use as little as one 
teaspoonful to four ounces of plain or dextrinized gruel 
(137) at the start. If this is well borne the quantity o f 
condensed milk should be rapidly increased. After the 
dilution has reached one 'to fifteen, equal parts of con- 
densed milk, and cream removed from a bottle of milk 
and mixed, should be used for dilution, which may be re- 
duced gradually to one to five or six parts of diluent (com- 
position about two to three per cent fat, one to one and 
one-half per cent proteid, six to eight per cent sugar). 
Whey and Cream Mixtures. 

150. Bartley's Formula : * From one quart of milk after 
the cream has risen siphon off the under three-fourths 
(this leaves the top eight ounces in the bottle). Place the 
under milk that was removed in a double boiler and "add 
a teaspoon and a half of good essence of pepsin and warm 
slowly to blood heat and keep at that temperature until 
thoroughly curdled. Now heat with constant stirring 
until a thermometer dipped into the milk shows a tem- 
perature of 1 55° F. and remove from the fire; strain, 
while hot, through a clean wire strainer and dissolve in 
the whey a heaping tablespoon of sugar of milk and the 
white of one egg. When cold pour the sweetened whey 

* Brooklyn Medical Journal, May, 1900. 



FOODS FOR DIFFICULT CASES. 273 

back into the milk bottle and mix thoroughly with the 
cream and top milk." 

" To reduce caseinogen we draw off more of the bottom 
milk. To increase it, draw off less. To decrease fat, dip 
off a part of the cream. ... To increase the fat, add a little 
less than the full amount of whey after removing the curd. 
To increase the soluble albumins, add more white of egg. 
The sugar may be varied at will by adding more or less 
as desired." The object of heating the whey to 155 F. is 
to destroy the rennet in the essence of pepsin that causes 
the milk to coagulate. Otherwise the top milk would 
curd when mixed with the whey. 

Westcott * has published some elaborate formulae for 
calculating the percentages of the fat, caseinogen, and 
lactalbumin in whey and cream mixtures, and a method 
of preparing mixtures. The principles involved are prac- 
tically the same as Bartley's, except that no white of egg 
is used. 

The original object of the whey and cream mixtures 
was to make a substitute food that should contain the 
same protein ingredients as human milk, assuming these 
to be definite proportions of caseinogen and lactalbumin, 
and thereby overcome the trouble caused by the curding 
of cow's milk. The experiments of White and Laddt 
led them to report " that whey has a distinct value as a 
diluent in making the casein coagulum finer, but is in- 
ferior in this respect to barley water." 

Since the analyses on which these schemes of prepar- 
ing food are based were published, much advanced work 

* International Clinics, October, 1900. American Journal of the Medical 
Sciences, October, rgoi. 

f Philadelphia Medical Journal, February 2d, igox, 



2J4 INFANT FEEDING. 

with the proteids of the milk of different animals has been 
done, and it is now known that the older belief as to the 
composition of milks and the proportions between casein 
and lactalbumin has been wrong, especially in the case 
of woman's milk (3 2 ). 

In many cases whey and cream mixtures are well borne, 
but the proteids of whey do not seem to have as much 
nutritive value as the proteids of the original milk from 
which it was made, it having been found in experiments 
in feeding two hundred and fifty-eight animals during an 
extended period that one part of skim milk produced as 
much gain in weight as two parts of whey ; and slaughter 
tests showed the flesh of the whey-fed animals to be in- 
ferior to that of those fed skim milk.* The great differ- 
ence will be seen by the following approximate comparison : 





Proteids. 


Sugar and salts 


Total solids. 




3.29 gm. 
I.74 " 


5-71 gm. 
n.58 " 


9.00 gm. 
13-32 " 







151. Whey. — Get some junket tablets at any grocery 
or drug store. Dissolve one of these in an ounce (two 
tablespoonfuls) of cold water and add this to a quart of 
fresh milk. Warm gently until a little above blood heat. 
When the curd has become quite solid beat up well with 
a fork and keep warm until the curds have shrunk con- 
siderably. Then strain off the whey and set on ice. 
Keeping the curd warm for ten or fifteen minutes greatly 
increases the yield of whey. Wine may be added as a 
flavoring agent if desired. 

* Henry . " Feeds and Feeding," p. 586. 



FOODS FOR DIFFICULT CASES. 275 

152. Peptonized Milk. Warm Process, — (1) Empty 
into a clean quart bottle the contents of one of Fairchild's 
peptonizing tubes ; (2) add four ounces (eight tablespoon- 
fuls) of cold water; shake, and (3) add one pint of cool 
fresh milk and again shake ; (4) place the bottle in water 
not too hot to be uncomfortable to the hand, for ten min- 
utes. Then either place on ice, or boil, to prevent further 
digestive action. This milk is likely to taste bitter. 

Cold Process. — Prepare the bottle as before, but set on 
ice without warming. This milk is only partially pepton- 
ized so will not have a bitter taste. 

153. Buttermilk. — For temporary use buttermilk has a 
field. It is best made at home by using one of the lactic acid 
ferments on the market. These consist of lactic acid bac- 
teria which, when placed in milk, produce lactic acid from 
a portion of the milk sugar, which precipitates the casein. 
Natural buttermilk contains little fat, as this has been re- 
moved as butter. In making buttermilk the cream may 
be removed and the ferment added to the skimmed milk, 
or whole milk may be used. 

Two types of buttermilk food are employed. First, 
the raw buttermilk, which contains enormous numbers of 
lactic bacteria; second, buttermilk to which one ounce of 
flour (four level tablespoonfuls) is added to the quart, and 
boiled. Raw buttermilk introduces harmless bacteria into 
the digestive tract which may kill off those present that 
are harmful. Cooked buttermilk supplies a fairly sterile 
acidified food in which the casein is finely divided and 
cannot form a solid mass in the stomach. 



276 INFANT FEEDING. 

Foods for Temporary Use Containing No Milk. 

154. In acute cases where no milk is tolerated it is best 
to try a thin dextrinized gruel (one ounce flour to quart', 
and if this is retained get back to milk feedings gradually 
by adding a teaspoonful of milk to a feeding of the gruel 
and increasing the quantity of milk a teaspoonful at a 
time. 

In chronic cases strong dextrinized gruels (two ounces 
flour to quart) may be used, and in some instances they 
will not only support life but cause gain in weight. An 
ounce of meat broth may be added to a feeding of the 
gruel to give flavor and make the food appetizing. Oc- 
casionally it may be advantageous to add white of egg or 
yolk of egg to the gruel. 

155. White of Egg and Dextrinized Gruel. — Add to 
eight ounces of dextrinized wheat flour gruel (137) the 
white of one fresh egg, and if well borne add one to two 
even teaspoonf uls of granulated sugar. Composition about 
2 per cent proteids and 4 to 7 per cent carbohydrates. 

156. Yolk of Egg and Dextrinized Gruel. — Add to 
eight ounces of dextrinized wheat flour gruel (137) the yolk 
of one fresh egg and if well borne one to two teaspoonf uls 
of granulated sugar. Composition about 1.5 per cent 
fat, 1.5 per cent proteids, 4 to 7 per cent carbohy- 
drates. These egg mixtures may be heated up to 150 F. 
without coagulating, hence they may be given warm if 
desired. 

For a number of malnutrition cases the use of legume 
gruels orbroths (p. 248) will be found helpful as they are 
rich in nucleoproteids. 



FOODS FOR DIFFICULT CASES. 277 

157. Egg Water— Beat up the white of one egg in 
eight ounces of cold water and add a pinch of salt. This 
may be flavored with a few drops of aromatic spirits of 
ammonia or of whiskey. 

Booker* has given the following formula: Egg water 
is made by beating the white of egg in a shallow dish, 
allowing it to stand for two or three hours, then pour- 
ing off the clear fluid, leaving the foam behind. The 
fluid is soluble in five parts of water. It should be diluted 
with a larger quantity of water when the digestion is 
feeble, and made palatable by the addition of sugar, salt, 
and a few drops of lemon juice. 

158. Beef Juice. — 1. Slightly broil a thick piece of steak 
that is free from the slightest trace of taint or sliminess ; 
cut in small pieces and press in a clean meat press or 
lemon squeezer. The yield of juice is not large. 2. Cut 
the meat into small squares and just cover with cold, 
slightly salted water, and set on ice for several hours. 
Then press by squeezing in a piece of cheesecloth (109). 

159. Beef Tea. — Cut a pound of lean meat into small 
squares and let stand in a pint of cold water for an hour. 
Heat to not above 160 F. and express the meat through 
cheesecloth. This tea will contain considerable nourish- 
ment. If heated higher, the proteids will coagulate. If 
the coagulum is fed, none of the nutritive value will be 
lost ; if removed, the tea will simply have a flavor. The 
nutritive value may be greatly increased by leaving some 
of the meat pulp in the tea. 

160. Meat Broths. — Take one pound of lean mutton, 
veal, or chicken with some cracked bone and cut into 
small squares; add one pint of cold water, heat gently 

• " Eleventh Annual Report of the Thomas Wilson Sanatorium for Children." 



278 INFANT FEEDING. 

and allow to simmer for several hours; remove all the 
fat. On cooling these broths will gelatinize (in). These 
broths, especially when thickened by the addition of 
flour, are highly nutritive. 

Food for Infants with Colic, Persistent Vomiting, 
Abnormal Stools, and Evidence of General 
Malnutrition. 

161. Colic may be caused by an excessive quantity of 
proteid in the food or by the infant not being kept warm 
enough, especially the bowels and extremities. The ex- 
cess of proteid in the food may be reduced by increasing 
the dilution. Persistent vomiting may be caused by feed- 
ing too great a quantity at a time ; from too much fat or 
cream in the food, or by poisonous products in the milk, 
the result of bacterial growth. Abnormal stools may con- 
tain curds of casein or fat, fermenting sugar, and mucus 
resulting from the undigested food irritating the intestine. 
Digestion is at a standstill and the infant is living partly 
on its own tissues, hence the malnutrition. 

As all these conditions are often seen at the same 
time, it is not always practical readily to discover the 
cause of the digestive disturbance. This belongs more to 
research work than to practical infant feeding. The prob- 
lem for the feeder is to nourish the infant and re-establish 
the digestive process. Here the natural order of develop- 
ment can be followed with advantage : 

i st. If the stools show signs of fermentation or putre- 
faction, clear out the intestines with a mild purgative (see 
Summer Diarrhoea) (170). 

2d. Supply nourishment that will be absorbed with lit- 
tle digestive effort and spare the infant's tissues. 



FOODS FOR DIFFICULT CASES. 279 

3d. When the stools become normal, gradually add 
food that will stimulate the flow of digestive juices and 
develop the functions of the stomach. 

162. When milk feedings cause digestive disturbance 
as just described, it is best to stop them at once and feed 
gruels, dextrinized gruels, or egg-water (137) ; these will 
generally be retained and assimilated, and furnish consid- 
erable nourishment. When the digestive disturbance has 
subsided, a teaspoonful of plain milk may be added to a 
two-ounce feeding and the quantity gradually increased 
and sugar added as fast as the infant's digestion will per- 
mit. In this class of cases the addition of lime water or 
syrup of lime until the food is alkaline to litmus paper 
may be beneficial ; one part of lime water to twenty parts 
of food is often used. It should be remembered that the 
syrup of lime is about thirty times as strong as lime water; 
hence one teaspoonful of syrup of lime equals about four 
ounces of lime water. 

163. When only small quantities of food can be di- 
gested, one teaspoonful of beef juice (158) may be added 
to a two-ounce feeding. This is slightly nourishing and 
acts as a digestive stimulant (13). Occasionally when 
highly diluted milk is not well digested a much smaller 
quantity of more concentrated milk food will be re- 
tained and digested, or peptonized milk (152) may 
succeed. 

When milk of any kind is not tolerated, white of egg 
and dextrinized gruel or yolk of egg with the same (156) 
may be tried. Occasionally dextrinized gruel will not be 
tolerated. Then resort may be had to whey, meat broths, 
or white of egg in water (157), getting back to milk feed- 



-So INFANT FEEDING. 

ings as soon as possible, always bearing in mind that the 
aim is to have the infant ultimately take between three 
and five per cent of fat, one and two per cent of proteids* 
(mixture one-third to one-half top milk), and five to eight 
per cent of sugar. 

164. Only general rules can be given for feeding these 
cases. They may be summarized as follows: 

1. Maintain nutrition with any form of food that will 
be readily absorbed (dextrinized gruel, whey, egg mixt- 
ure). 

2. When the stools become normal, give food that will 
gradually re-establish the digestive process (add small 
quantity of milk). 

3. Return to milk feeding (i39\as soon as possible. 

4. The fact that all the food that is utilized combines 
with the oxygen of the air we breathe should not be over- 
looked, and hence attention should be paid to the air sup- 
ply as well as to the food. 

It should be remembered that fats retard gastric secre- 
tion, and that excess of sugar promotes the flow of an 
acid gastric juice ; therefore these ingredients should be 
reduced in quantity when there is gastric disturbance. 
Excessive vomiting may be due to mucus in the stomach, 
which may be removed by stomach washing (165) ; or to 
nephritis. In all forms of fevers, fats should be reduced 
in quantity, and easily assimilated carbohydrates in the 
form of dextrinized gruels (137) supplied along with milk, 
to reduce as much as possible the excessive destruction of 
protein tissues that takes place in fevers (13, 14, 19, 25). 



CHAPTER XXIV. 

FEEDING BY GAVAGE— NASAL FEEDING-REC- 
TAL FEEDING— FEEDING PREMATURE IN- 
FANTS. 

165. Cases are not infrequently met with in which an 
infant cannot or will not take sufficient nourishment by 
swallowing. It will then be necessary to feed wholly or 
in part by the stomach tube. This proceeding is often 
easier than it looks; all -that is needed is a glass funnel, 
to which is attached a short rubber tube, and this to a soft 
catheter, by a short piece of glass tubing placed between 
the rubber tube and catheter, so that the flow of the fluid 
can be seen. The infant is placed in a recumbent posi- 
tion, with the arms bandaged to the sides of the body or 
fastened by a towel tightly pinned around ; an assistant 
steadies the head, and the tube is quickly passed through 
the mouth ; when it reaches the back wall of the pharynx 
a little force is required to deflect it downward, when it is 
easily passed into the stomach. In cases in which the ton- 
sils are much swollen, as in diphtheria, the tube may be 
passed through the nostril, taking care to pass the tube 
through the inferior meatus along the floor of the nose. 
It is sometimes a little more difficult to get the tube 
through the nose, besides being apt to cause more dis- 
comfort. Fluid will flow more readily when the tube is 
full as it passes into the stomach. Otherwise the column 



INFANT FEEDING. 




Fig. 80. ^Stomach Tube 



of air in the tube may offer some resistance to the flow of 
the nutrient fluid. This can be obviated by filling the 
tube with warm water or the fluid food, and then pinch- 
ing the tube just below the funnel. The fluid will then not 
run out of the tube, which can be passed into the stomach ; 
when it is in place 
the funnel is filled, after 
which the grasp on the 
tube is relinquished, and 
the fluid will easily flow 
into the stomach. When 
the tube is withdrawn, 
it should be pinched 
again to prevent drops 
trickling out and irri- 
tating the pharynx, as vomiting may be caused by 
such irritation. 

It is better to give nourishment in rather higher 
dilution than has been usual for the infant; often 
partly digested food is required when gavage is 
employed. The intervals between feeding should 
also be longer than when nourishment is given by 
natural means, and the stomach must not be filled 
too fast. Where gavage is continually employed, 
the stomach should be washed out every day or so with 
warm water before feeding, as, by removing mucus or 
particles of food, digestion and absorption are improved. 

In stomach washing, pour in water through the tube 
as in feeding. Then lower the funnel so that the water 
can siphon out of the stomach. 

Premature infants and atrophy cases at term may 



FEEDING BY GAVAGE. 283 

sometimes be fed to advantage by gavage ; also harelip or 
cleft-palate babies, who swallow with difficulty ; and after 
certain operations upon the mouth. Some badly nour- 
ished babies absolutely refuse to take sufficient nourish- 
ment, which may be corrected by the use of the stomach 
tube. The author has seen cases in which one or two full 
feedings thus given was followed by the baby voluntarily 
taking a proper amount. In meningitis, and when there 
is complete or partial unconsciousness from any cause, 
gavage may be employed with good results. The same 
may be said of diphtheria accompanied by much swelling 
of the throat, and particularly after intubation. In the 
latter case, feeding by gavage should always be employed, 
at least for the first day or so. Later on the child may 
be cautiously spoon-fed with the head in a low position, 
and viscid substances, like condensed milk, are less apt 
to penetrate the tube. Finally, persistent vomiting is 
sometimes relieved by one or two feedings by gavage. 
When the stomach tube has been used for any cause, the 
child should be kept very quiet in a horizontal position for 
some time afterward ; the chance of vomiting will thus be 

much lessened. 

Rectal Feeding. 

166. There is a great difference in the tolerance of the 
rectum to attempted feeding in the infant as in the adult. 
At times, such as in extreme gastric irritability or 
when there is local obstruction, as in diphtheria or retro- 
pharyngeal abscess, it is often desirable to stop for a time 
all nourishment by the mouth. In such cases we must 
bear in mind the fact that the rectum can absorb but not 
digest food, and that small amounts will often be retained 



I 



284 INFANT FEEDING. 

when larger amounts are rejected. The lower bowel 
must first be cleaned by a moderate injection of warm 
salt solution or soap suds and water. From one to two 
ounces of the nutrient solution may then be very slowly 
injected, with the buttocks slightly raised and tightly held 
on either side of the nozzle of the syringe. When the 
nozzle is withdrawn the buttocks had better be held in 
close apposition for a few moments, to prevent a leaking 
out of part of the enema. In cases in which 
the rectum is intolerant, a very small amount, 
such as two or three drachms, will some- 
times be retained. The occasional addition 
of a fraction of a drop of deodorized tinct- 
ure of opium to the nutrient enema will 
help to quiet an over-irritated rectum, but 
the susceptibility of very young infants to 
the constitutional effects of opium must 
always be borne in mind. When the enem- \ijj 
ata are given at regular intervals, the prelim- V v 
inary washing need not be employed after FlG . 8l . _ Re ctai 
the first time, as this increases the irritability 
of the bowel. Easily absorbable nutriment must always 
be employed, such as dextrinized gruel, dextrinized gruel 
with white of egg (155), completely peptonized milk, or 
expressed beef juice and water. In cholera infantum, 
where the quick loss of fluid from the blood-vessels threat- 
ens life, the injection of a hot saline solution into the 
bowel sometimes affords relief. Here again a small 
amount is often preferable, as two or three ounces, or 
even half an ounce, may be retained and absorbed, when 
a pint may be quickly rejected. 



FEEDING BY GAVAGE. 285 

Feeding of Premature Infants. 

167. The difficulty of nourishing premature babies 
consists in the incomplete development of their digestive 
tract, and the difficulty of keeping them warm while at 
the same time supplying sufficient fresh air. They are 
exceedingly dependent upon pure air, and here it is that 
most incubators fail. The author has treated over fifty 
premature infants in incubators at the Babies' Wards of 
the New York Post-Graduate Hospital, but with poor re- 
sults. This is attributed to two factors — the absence of 
the breast, calling for exclusive artificial feeding ; and the 
delay in getting them, many of the babies being blue and 
cold from exposure in transporting them to the hospital 
when received. The author has tried all kinds of incuba- 
tors, and believes that only those having a fresh-air inlet 
connected with the outer air are safe to use. The Lyon 
incubator is a good example of this type. If such an in- 
cubator is not obtainable, an ordinary soap box may be 
improvised, in which the baby is placed, done up in cot- 
ton and surrounded by hot-water bottles. The top of the 
box may be partially covered with a sheet or towel, so ar- 
ranged as to allow free access of fresh air. The babies at 
first seem to do best at an average temperature varying 
from 85° to 90° F. The less the infant is disturbed the 
better ; at the same time proper cleanliness of the baby 
and incubator must be insisted on, as these infants are 
very vulnerable to infection of all kinds. The most im- 
portant factor in raising them is to secure breast milk. 
The milk must be drawn from the breast after the colos- 
trum period, the preferable time being from about eight 



286 INFANT FEEDING. 

days to a month or so post partum. This milk must 
usually be diluted one-half with boiled water or sugar- 
water solution. The best way, in the author's experience, 
to administer fluid to these babies is by means of a medi- 
cine dropper. This must be done very slowly, drop by 
drop, taking care to see that the motion of swallowing is 
accomplished after each drop before giving another. This 
extra care is required from the tendency of the fluid to 
get into the windpipe. The author has seen a number of 
deaths from this cause, as shown by autopsy. 

When the infant is too feeble to swallow, a small 
catheter used as a stomach tube must be employed. It 
can be passed without removing the baby from the incu- 
bator, and does not seem to cause it much disturbance. 
As soon as the baby grows older and is strong enough, 
a small nipple may be substituted. The exact amount 
to be given a premature baby must depend upon the pe- 
riod of utero-gestation and its apparent development. In 
one case, weighing only two and a half pounds, a drachm 
every hour was given by the author, with good results. 
In better-favored cases, from four to eight drachms can 
be given every hour or two. If the infant thrives, in two 
or three weeks it can be given pure breast milk at two- 
hour intervals. Where it is impossible to get breast milk 
the chances of the premature baby will be very poor, but 
efforts must be made in the line of artificial feeding. 
Both the fat and proteids of cow's milk are digested with 
difficulty in these cases, so they must be given in very 
small amounts. The milk must be diluted to represent 
fat i per cent, sugar 3 per cent, proteids 0.33 per cent 
(one-tenth nine-ounce top milk plus one-thirtieth sugar), 



FEEDING BY GAVAGE. 287 

of which a drachm may be tentatively given every hour ; 
if tolerated, gradually increase the amount. If the baby 
is at the eighth month, a little stronger mixture may be 
borne, such as fat 1.5 per cent, sugar 5 per cent, proteids 
0.50 to 0.75 per cent (one-eighth to one-fifth nine-ounce 
top milk plus one-twenty-fifth sugar). Such a case may 
take from four to six drachms every hour and a half. 
The exact amount must depend upon the general devel- 
opment of the baby, bearing in mind that the stomach of 
the baby at term has a capacity of about an ounce. Some 
cases cannot digest ordinary cow's milk, and then a trial 
may be made of whey, expressed beef juice, egg water, or 
highly diluted condensed milk. In a case recently seen 
with Drs. Hurlburt and Sherill, of Stamford, Conn., a 
feeble incubator baby was successfully fed with undiluted 
ass' milk for about a month, gaining in weight and 
strength. This milk then giving out, the baby was put 
on a wet-nurse and continued to thrive. 



CHAPTER XXV. 
CONSTIPATION. 

168. Constipation as well as diarrhoea are relative 
terms, and refer more to the character than the frequency 
of stools. A constipated stool in an infant is usually dry 
and hard and voided with some difficulty. One or two 
such stools may be passed daily with evidence of intesti- 
nal discomfort, and call for dietetic treatment. In the 
nursing infant the mother is herself frequently consti- 
pated, and treatment must first be directed to her, as 
when she is properly regulated the infant may need no 
further attention. Stewed fruit, figs, prunes, oatmeal and 
cream, unbolted bread, and similar articles of diet may be 
tried with the mother, with plenty of outdoor exercise. 
It may be necessary to cut off milk in part, or to give it 
diluted with oatmeal gruel to which cream is added. A 
glass of cold water or Vichy immediately upon rising has 
a favorable effect in opening the bowel. Tea should be 
avoided. If these measures do not suffice, some of the 
tonic laxatives, such as cascara, aloin, mix vomica, and 
hyoscyamus may be tried. The commercial mixtures of 
malt extract and cascara are usually efficient and agree- 
able. 

When the mother has been regulated and the infant 
remains constipated, there is usually a deficiency of fat in 
her milk, often accompanied by a high percentage of pro- 
teids. If this cannot be corrected by a meat diet and 



CONSTIPATION. 289 

plenty of exercise (20), a little fat may be administered 
to the baby just after nursing. A small teaspoonful of 
cream two or three times daily given in this way may 
correct the infant's constipation; a half-teaspoonful of 
sweet oil will also serve the same purpose. The efficacy 
of the oil is sometimes increased by combining with it a 
little sugar and water, a small lump of loaf sugar being 
dissolved in a teaspoonful of water and given with the oil. 
A half teaspoonful of cod-liver oil may also be employed 
in the same way. 

The nursing baby may be constipated from the moth- 
er's milk being deficient in both fats and proteids, or 
from an insufficient quantity of it. If efforts to correct 
this condition fail, it may be necessary to supplement the 
breast by the bottle in order to increase the volume of the 
stool (27) and thus relieve the constipation. As a rule, 
bottle-fed babies are more apt to suffer from constipation 
than those on the breast. In the former cases the condi- 
tion may be corrected by increasing the fat in the feeding 
mixture. According to the dilution often recommended 
for young babies, the fat barely reaches two per cent when 
poor milk is used in making the mixture. By using less 
diluent or a richer top milk (132), we may run the fat up 
to three per cent and thereby improve nutrition as well as 
relieve constipation. During the first six months or so of 
the first year the baby usually thrives best on a mixture 
containing three per cent fat and one per cent milk 
proteids, while later in the year four per cent fat and one 
and one-half to two per cent milk proteids are indicated 
p. 263. The neglect to administer percentages suitable to 
the age and condition of the infant is responsible for a 
19 



2Q0 INFANT FEEDING. 

good deal of constipation, a habit it is sometimes difficult 
to correct even when the cause is removed. A change in 
the diluent employed will sometimes be necessary; if gru- 
els are used, oatmeal is more laxative than barley or 
wheat flour. Infants of a year old may be given chicken 
tea, which is somewhat laxative, and beef tea may have 
the same effect; expressed beef juice sometimes favors 
an action of the bowels. A teaspoonful to a tablespoon- 
ful of orange juice given in the morning often has a laxa- 
tive action upon the infant. The free use of water, be- 
tween nursings or feedings, tends to prevent too great 
consistency of the stools, one of the common accompani- 
ments of constipation. 

For children of two or three years, fresh fruit, such as 
apples, peaches, and oranges, may be given in the morn- 
ing ; stewed fruits of all kinds are allowable, and dried 
fruits, such as prunes, figs, and dates, often do good ser- 
vice. The following method of treating prunes, given the 
author by Dr. Cauldwell, has often produced favorable 
results: Fill a preserve jar one-half or three-quarters full 
of fresh California prunes, and pour in boiling hot water 
to fill the jar; next close the jar and stand in a warm 
place for six or eight hours. During this time the 
prunes become full and swollen and the pulp is very soft. 
The water is then drained off and the primes are spread on 
a plate so that the skins may dry quickly. They are now 
ready to eat ; split open and use the pulp only. Give the 
pulp of three to six prunes before breakfast each morning 
with a glass of cold water. The laxative effect of the 
prunes is thus much enchanced, and they are usually 
readily taken in this form by children. 



CONSTIPATION. 291 

Crandall has stated that for constipated babies it is a 
good plan to give prunes that have been boiled with a 
few senna leaves. 

The following " Fruit Tablets " are agreeable and effi- 
cacious : Take four ounces each of raisins, figs, and dates, 
and two ounces of ground senna leaves; remove the 
seeds from the raisins and dates, and finely chop the fruit ; 
then mix on a table, adding the senna to the chopped 
fruit little by little, putting in sherry enough to make a 
paste ; roll into a mass half an inch thick, and cut into 
half inch squares; place the tablets between sheets of 
paraffin paper in a box. One or two of these tablets may 
be given at night and repeated in the morning if neces- 
sary to get the result. 

It may be desirable to curtail the milk in cases of ob- 
stinate constipation or to add cream to what is taken. 
The coarse cereals, such as oatmeal, unbolted bread, and 
all the green vegetables, may be given at two years. 
These foods, by their saline and fibrous contents, have a 
stimulating effect upon the mucous and muscular coat- 
ings of the intestine, and increase the quantity of fecal 
matter (27). 

Very often the trouble consists in a sluggish action of 
the unstriped muscular fibres of the bowel, which suit- 
able diet is not sufficient to correct. Deep massage of the 
bowel, beginning at the right iliac fossa and extending 
around the course of the large intestine, may aid muscu- 
lar action if thoroughly performed twice daily. The use 
of suppositories and injections also stimulates the muscles 
to more vigorous action. For occasional use, glycerin 
suppositories are very efficient, but if employed too fre- 



2Q2 INFANT FEEDING. 

quently are apt to irritate the rectum. For continued 
use, gluten or soap suppositories serve best. The fault in 
constipation of young infants is often at the lower end of 
the large intestine. Owing to the length of the sigmoid 
flexure during infancy, this part of the bowel is sharply 
curved, with a resulting tendency to retard the descent 
of fecal matter just above the outlet of the bowel. A 
bland suppository, or even passing the end of a finger 
through the anal ring, will often cause the bowel to empty 
itself. The passage of a healthy digested stool after such 
a manipulation will prove that there is no essential fault 
in diet or digestion, but simply a sluggishness at the end 
of the bowel. If fecal matter is higher up, an injection 
of two or three ounces of soap suds and water, salt and 
water, or sweet oil and water will be required for relief. 
In obstinate cases a teaspoonful of glycerin in an ounce 
of water will usually have a quick effect. 

A constipated infant should be constantly observed 
and treated until the condition is relieved, as most of the 
chronic cases in later life have their beginnings in early 
life. No structure of the body is more amenable to habit 
than the bowel ; hence the importance of starting right. 
As soon as the baby can stand, it should be placed upon 
the chair or chamber at regular intervals. Yale has 
called attention to the importance of placing the child 
upon a low seat with the feet upon the floor, as it can 
then strain to better advantage. 



CHAPTER XXVI. 

SUMMER DIARRHCEA. 

169. The cause of the diarrhceal diseases of infancy 
so common during the summer months is not positively 
known, though there can be little doubt that they are of 
bacterial origin. Just where the bacterial infection origi- 
nally takes place is hard to tell, although in many cases it 
is undoubtedly local. It has been generally believed in 
the past that the high temperature of the summer months 
was the cause of the diarrhceal epidemics. Heat does 
play an important part, especially in depressing the diges- 
tive function, but in the summer of 1 901, which was an 
exceptionally hot one, the number of deaths from diar- 
rhceal diseases of infants throughout New York State, 
outside of the district including Greater New York and 
its suburbs, was only a little over half of that of the pre- 
vious summer, which was not so hot. The amount of 
rainfall also seems to have little or no effect on the num- 
ber of deaths from diarrhceal diseases of infancy. 

The milk supply has come in for its share of condem- 
nation as the principal cause of diarrhceal diseases; un- 
doubtedly the milk supply is a prominent factor, but 
there must be still other sources of infection, as breast-fed 
infants are sometimes attacked. 

If the milk supply was the exclusive cause of the dis- 
ease, there should be a larger proportionate number of 



294 INFANT FEEDING. 

deaths in cities like New York, whose milk is twenty- 
four to forty-eight hours old when received, than in the 
country where the milk is produced. New York's milk 
supply is drawn from a wide range of country, but it is 
found on examining the death statistics that in some years 
there is a great increase in the number of deaths in the 
country districts where the milk is produced, and only a 
slight increase in Greater New York; in other years an 
increase in the country and a falling off in the city is 
found, as will be seen by the following figures obtained 
from the New York State Board of Health: 



Deaths from Ac 


ute dlarrhceal diseases, 
Inclusive. 


May 


[st to November ist, 




1892. 


1893. 


1894. 


1895. 


1896. 


1897. 


1898. 


1899. 


igoo. 


1901. 


Country districts. . 

Greater New York 

and suburbs .... 


2,550 
5,943 


2,721 
5,477 


3,046 
5,244 


2,727 
5,559 


3,o39 
4,908 


2,086 

4,34o 


2.S33 

4,868 


2,187 

3,557 


3,202 

3,867 


1,898 
6,115 



It is improbable that there is enough variation in the 
methods of handling milk from year to year to account 
for this fluctuation in the number of deaths. There 
must be some local infection. In 1901 the Borough of 
Manhattan of the city of New York was torn up from one 
end to the other for the purpose of building a subway. 
Sewers were opened and changed, and dust was every- 
where. In the country districts, where the milk was pro- 
duced, there was a large falling off in the number of 
deaths from diarrhceal diseases, as previously mentioned, 
while in the district which included Manhattan the num- 
ber of deaths was almost double that of the previous 
year. It is evident that there must have been a local in- 
fection that caused this (62). 



SUMMER DIARRHCEA. 



295 



At the Wisconsin Experiment Station there has been 
worked out what is known as a curd test, by which the 




Fig. 82. — Rennet Curd of Milk when Lactic Bacteria Predominate. (Russell.) 

character of the bacterial changes in the milk may be de- 
termined and the source of the infection located. 

A sample of milk is curded by rennet, and the whey 
which contains most of the sugar of the milk drained off; 
the curd is then kept at a temperature of about ioo° F. 
for several hours. 




Fig. 83 — Rennet Curd of Milk when Gas-Producing Bacteria Predominate. (Russell.) 

The normal fermentation of milk is souring, in which 
the sugar is changed into lactic acid by lactic bacteria; 



2Q6 INFANT FEEDING. 

when this change takes place the curd becomes firm and 
uniform in texture. However, if decomposition or other 
kinds of bacteria that attack proteids (54) are present, 
they find favorable conditions for growth in the curd 
which contains little sugar, and soon outstrip the lactic 
bacteria in growth (52) . Their presence is shown by the 
production of gas, which causes the curds to rise like 
bread dough, or in foul offensive odors resulting from the 
decomposition of the proteid of the curd. 

Both of these abnormal fermentations are very com- 
mon in milk during July and August, the months in 
which there is generally the greatest number of deaths 
from diarrhceal diseases. 

At cheese factories these bacterial changes are partic- 
ularly troublesome, and a great deal of time and study 
has been devoted to locating the source of the infection. 
The curd test has proved to be valuable for this purpose. 
By making a curd from the milk of each farmer and re- 
jecting the milk that produces gassy or foul curds, it has 
been possible to overcome the trouble. By following this 
same method with the milk of each cow, it has been pos- 
sible to discover the infectious material, which is almost 
invariably dust or filth. It has been found that no mat- 
ter how much care has been devoted to producing the 
milk, if it becomes slightly infected with dust or filthy 
water that contains these bacteria, they will rapidly grow 
and elaborate their characteristic products. 

In cases of summer diarrhoea there is generally a great 
deal of gas formed in the intestine, and many thin, sour 
stools containing undigested curds of milk are passed. 
In some instances the stools which contain undigested 



SUMMER DIARRHOEA. 297 

curds are few but very foul and offensive, indicating a 
decomposition of prpteids. Here are seen all the 
changes that result from dust and filth infecting milk. 

For this reason not only must care be exercised in the 
production of milk at the farm, but it should not be 
opened until delivered \o the family ; and in the family 
care should be used to K.eep all utensils absolutely clean. 
Pasteurizing the food is one step toward preventing the 
growth of these bacteria ; but, if they gain access to pas- 
teurized food or milk, they grow even better than in fresh 
milk. Koplik has called attention to this question and 
to the necessity of the mother or nurse carefully washing 
her hands after changing an infant's diapers, as she may 
easily infect the nipple or the food in this manner. The 
soiled napkins should be immediately placed in a satu- 
rated solution of chloride of lime and allowed to soak be- 
fore being washed. 

There can be little error in concluding that contami- 
nation at the farm is an important factor in infecting the 
milk; also that dust, contaminated water, soiled hands, 
and possibly flies at the home are also dangerous. The 
greater or Jess infection of the milk from these sources 
after leaving the farm is the probable cause of the varia- 
tion in deaths from diarrhceal diseases from year to year 
in city and country. 

Nature of Summer Diarrhoea. 

170. The discovery that the dysentery bacillus of 
Shiga was present in the stools of infants suffering from 
summer diarrhoea led to the belief that this bacillus was 
the cause of the disease, and great hopes were entertained 






298 INFANT FEEDING. 

of producing- an antitoxic serum for use in treatment. 
Very careful studies have shown that there are at least 
two different kinds of dysentery bacilli and that there 
must be a serum used for each kind ; as yet no satisfac- 
tory serum has been made. La Fetra and Howland have 
reported a clinical study of sixty-two cases of infection 
with bacillus dysenteriae (Shiga) occurring in breast-fed 
and bottle-fed infants. 

No clinical picture that is peculiar to this infection 
was discovered. The symptoms ranged from those of 
simple intestinal indigestion to those of acute summer 
diarrhoea. One thing prominently brought out was that 
well-nourished infants that had good digestion were the 
least affected, while those who were poorly fed artificially 
had the most severe symptoms. Twenty per cent of the 
cases were breast fed, but " not one of them was severely 
or even moderately ill." Properly nourished infants will 
not be very susceptible to these infections, and, if attacked, 
will with proper eliminative and dietetic treatment be able 
to produce their own natural antitoxins, which is desirable 
in view of the fact that each bacillus calls for its own spe- 
cific antitoxin. 

There seem to be bacteria present in the diges- 
tive tract at all times, but their growth is retarded or at 
least not harmful when digestion proceeds normally. 
During the heated term all the vital functions are de- 
pressed and digestion proceeds slowly. The milk curds 
in the stomach normally, and the whey containing the 
sugar is expressed (37). If fermentation instead of di- 
gestion takes place, the lactic bacteria have a free field in 
the whey, and the putrefactive or gas-producing bacteria 



SUMMER DIARRHCEA. 299 

in the curds, where they are protected from the action of 
what little digestive juice is secreted. Products of pro- 
teid decomposition resulting from such conditions are 
apt to be poisonous (54), and it is not at all uncommon 
to see all the symptoms of toxaemia in infants and chil- 
dren with diarrhceal diseases, especially when the stools 
are offensive. Therefore these diarrhoeas should be 
looked upon as cases of indigestion with a digestive tract 
filled with fermenting and putrefying food. 

As previously stated (169), the cleanest milk or pas- 
teurized milk is quickly rendered harmful by only a slight 
contamination with this putrefying material ; it is there- 
fore worse than useless to put any more milk or other 
food that will putrefy into such a digestive tract as long 
as this putrefying material remains. It would only aggra- 
vate the trouble. The diarrhoea is an attempt of nature 
to get rid of the offending matter. 

The treatment of this disease consists of giving a mild 
purgative thoroughly to remove the putrefying intestinal 
contents, and then re-establishing the digestive process. 
To many mothers the giving of a purgative to an infant 
with diarrhoea seems folly, but it is absolutely essential to 
successful treatment, and if the mother cannot be trusted 
to give it, the doctor should do so himself. 

During an attack of summer diarrhoea the infant's 
food should be carefully looked after. The promptness 
of recovery will depend largely on this, for as soon as the 
digestive process ceases, owing to the infection, the infant 
begins to live on its own tissues and there is a great and 
sudden increase of protein metabolism, as the protein is 
used as a fuel. In infants that have been on a diet poor 



300 [NFANT FEEDING. 

in protein this is particularly disastrous, as they have little 
reserve protein to draw on. Such infants quickly succumb. 

The aim in feeding' should be to sustain the infant by 
the use of food (i) that will not form a culture medium 
for putrefactive bacteria, and (2) that will prevent the 
abnormal destruction of protein tissue, which is especially 
large where there is fever. For this purpose carbohy- 
drates stand pre-eminent, and in the author's experience 
gruels, especially when dextrinized (137), are the best 
forms in which to give them. These contain a small 
quantity of protein in a form that will not easily undergo 
putrefaction, and enough carbohydrates in a form suitable 
for prompt absorption to sustain the infant and prevent 
its own tissues being destroyed to any extent. Much 
more nourishment can be given in the form of dextrinized 
gruels than in plain cereal waters. If any fermentation 
takes place in this food, poisonous products are not 
formed, as carbohydrates predominate, which bacteria 
change into lactic acid, that is not harmful. When 
dextrinized gruels cannot be had, egg water (157) may be 
used, but this supplies only about one-fourth as much 
nourishment as the dextrinized gruel. The products of 
egg metabolism, principally urea, must be excreted by the 
kidneys, which are often congested and irritated by the 
toxins absorbed from the intestinal tract ; and, in addi- 
tion, by the urine, which is concentrated and scanty, 
owing to the large loss of fluid from the bowels. The 
products of carbohydrate metabolism pass off through 
the lungs. 

White of egg is a pure protein substance and should 



SUMMER DIARRHCEA. 301 

be used cautiously when the stools are foul, but may be 
used freely when they are very sour (52). 

Kerley, after studying several hundred cases of sum- 
mer diarrhoea, came to the conclusion that on a carbohy- 
drate diet there was less systemic poisoning, recovery was 
more prompt, and temperature lower than on a protein diet, 

Treatment and Diet in Summer Diarrhoea. 

171. First: Clean out the digestive tract by doses of 
castor oil (one teaspoonful) or divided doses of calomel 
(one-tenth grain every hour until one grain has been 
taken). If the stools are few and foul, the bowel should 
be irrigated with a quart of tepid salt solution (one tea- 
spoonful to a quart), to hasten the removal of the putrid 
matter. A fountain syringe with hard-rubber tube 
should be used, and the water allowed to flow in gently 
until it runs out clear. 

Second : Stop all milk food of any kind, and offer 
boiled water; if this is retained, feed the same quantity of 
dextrinized gruel or egg water (137) as the usual milk 
feeding, at two-hour intervals. Rice is one of the best 
cereals for this purpose, as it is absorbed almost com- 
pletely. Rice flour or one of the flaked-rice preparations 
(102) may be used in preparing the gruel, as these can be 
cooked in a few minutes. Barley and wheat flour come 
next in order. If the gruel produces sour acid stools, try 
egg water (157) or mutton broth (160). When the stooh 
become normal, a teaspoonful of milk should be added to 
a feeding of the gruel, and the quantity cautiously in- 
creased until the usual mixture is taken. Often not a 
drop of milk will be tolerated for a long time. In these 



302 INFANT FEEDING. 

cases a strong dextrinized gruel may be used for nourish- 
ment, and to prevent the infant tiring of it, barley, rice, 
or wheat may be used alternately. Mutton broth (160) 
or beef juice (158) may be added in small quantities to 
act as flavoring agents and promoters of digestive secre- 
tion. Care must be exercised in giving meat broth or 
juice in these cases. Doming has called attention to 
severe ptomain poisoning from the use of beef juice made 
from tainted meat; and in too large quantities the meat 
extractives (13) have a decidedly laxative effect. 

Dv7tgs to be Used. — Subnitrate of bismuth is the prin- 
cipal one used, aside from castor oil and calomel. It 
should be given until the stools become black. Opium 
has its place, but should not be used before the intestine 
has been thoroughly cleared. Alcohol may be used up 
to the point where it can be detected in the breath in 
cases of great prostration, but many mothers are apt to 
give too much, which interferes with digestion and also 
throws additional strain on the kidneys in excreting it. 

Preventive Measures. — Fresh air, cool sponge baths, 
and light diet are good preventive measures. The author 
often advises allowing the smaller children to play in a 
bathtub containing tepid water daily in hot weather. 
Care should be exercised in having the abdomen kept 
warm at night with a light flannel band when there are apt 
to be sudden changes of temperature, as cold may be the 
starting-point of summer diarrhoea. 



CHAPTER XXVII. 
DIET DURING SECOND YEAR. 

172. The diet during the second year requires careful 
consideration, as this is a period of transition between the 
breast or bottle and the ordinary mixed diet of later child- 
hood. It is a time of rapid growth, with cutting of teeth, 
when new functions are inaugurated, all of which require 
watching. The common mistake in feeding is to allow 
too great a variety, thus taxing the digestive powers at a 
time when they can ill afford to be strained. Cow's milk 
must still form the basis and most abundant article of 
diet. 

The cutting of teeth indicates that the chemical por- 
tion of the digestive process (5) has been established 
and that the mechanical function (5) is being devel- 
oped. The infant is prepared chemically to change 
many of the articles of diet that the mother eats, but it 
cannot yet prepare them so that they will be acceptable 
to the digestive tract. Meat should be finely divided be- 
fore being swallowed, and until a full set of teeth is pro- 
vided for this purpose the dividing must be done by the 
nurse or mother. 

The nutriment of vegetable substances is enclosed in 
cellulose (10), which even the mother cannot digest 
except to a slight extent. Therefore vegetable food for 
infants must be well cooked to burst open the indiges- 



3 o 4 INFANT FEEDING. 

tible cells. For this reason only tender vegetables or 
cereals should be used. A clear idea of the difference 
between vegetables in this respect may be had by tasting 
the tender tip of boiled asparagus and the woody butt of 
the stalk. All vegetable substances for infants and chil- 
dren should be cooked until they are as tender as aspara- 
gus tips. 

Fruits of various kinds are early allowable, such as 
orange juice, apple sauce or baked apple with the skin 
removed, stewed dried apples, and stewed prunes after 
the pulp has been squeezed through a sieve. These arti- 
cles are not only digestible, but have a favorable action 
on the bowels. 

At the end of the first year we may start with one 
soft, semi-solid meal during the clay, this to take the place 
of one bottle. As the infant grows and shows an ability 
to digest this kind of food, a second similar meal may be 
substituted. 

A thin pap, made by soaking stale bread crumbs or 
zwieback in hot water and adding this to milk, affords a 
good beginning for spoon food. A fresh egg (113) boiled 
for two minutes and thoroughly stirred with bread or 
cracker crumbs is likewise generally relished. The 
cereals cooked to a jelly, salted, and covered with milk 
make a very good meal. From a nutritional standpoint 
oatmeal is to be preferred, but some infants seem to ob- 
ject to its taste. If when it is used there is a tendency to 
intestinal fermentation or irritation of the skin, it had 
better not be employed. The higher grade of rolled oats 
sold in packages should be selected, as they contain less 
husk, which is irritating to the intestines. While ordi- 



DIET DURING SECOND YEAR. 305 

nary oatmeal requires many hours of cooking (102) these 
rolled oats can be thoroughly cooked by half an hour's 
boiling in a covered double boiler if plenty of water is 
used, so that each particle of oat becomes soaked before 
the boiling temperature is reached. 

Sometimes an infant will readily take one cereal while 
rejecting another, or will tire of one preparation after a 
certain amount of use, and hence require a change. 
Among the better known prepared cereals that may be 
used are Quaker Oats, Hornby's Steamed Cooked Oat- 
meal, Germea, Pettijohn's Breakfast Food, Wheatena, 
Whole Wheat Gluten, Pearl. Hominy, Force, and Cook's 
Flaked Rice. Analyses of these and other cereals will be 
found in another place (page 165). Oatmeal is richest in 
fat and protein ; gluten comes next, and wheat, hominy, 
and rice follow in respective order. It is not too much 
again to mention the necessity of boiling these cereals 
with plenty of water. No attention should be paid to the 
extravagant claims made for some of the prepared foods. 
There is very little difference between any of them of the 
same class in nutritional value. 

None of the so-called " ready-to-serve " breakfast foods 
should be given to infants until they have been boiled 
fifteen minutes. 

Meat broths (160) may be started with the beginning 
of the second year, using preferably those made from 
mutton or chicken. 

Between eighteen months and two years the adminis- 
tration of small amounts of meat may usually begin; 
scraped beef, rare roast beef, broiled beefsteak, roast 
lamb, broiled mutton chop, white meat of chicken, 



>o 






3 o6 INFANT FEEDING. 

and fresh fish, boiled or broiled, may all be employed. 
Meat must be given rather sparingly at the beginning 
and always finely minced (108), the amount depending 
upon the outdoor life and exercise the child may be get- 
ting. At about the same period the following vegetables 
may be allowed — thoroughly baked potatoes, spinach 
passed through a colander, string beans, peas, asparagus 
tips, boiled onions, and celery stewed in milk. All vege- 
tables must be very thoroughly cooked to a pulpy consis- 
tency, in order to soften and disintegrate the cellulose 
(Fig. 45) and thus render them more digestible. 

Sample Diet for Child of One and One-Half to Two Years. 

1 Glass of milk ; cereal ; a thin slice of stale bread with butter or 
7 to 7:30 a.m. - . , . 

' J ( zwieback. 

j T Ai M Glass of milk or cup of meat broth. 

r Meats or fish — any mentioned in previous paragraph. 

I Potatoes thoroughly baked or mashed — at first once or twice 

2 to 3 p. M -j a week. 

j Any succulent pulpy vegetable, slice of bread and butter, and 

one of the milk puddings. 

^ Stale bread and milk, or cereal and milk, or slice of bread and 

' ' "" ( glass of milk ; stewed fruit. 

Tea or coffee should never be given. 

Such a dietary can be maintained from the age of two 
to three or four years. It is naturally only suggestive 
and will need modifications in individual cases, both as to 
the periods of time and articles of diet. At the begin- 
ning, most little children will require one night feeding, 
and then a bottle of plain or modified milk (137) can be 
given at 10 or 11 p.m. 

Much judgment is often required in starting the 
young child on a diet after the bottle has been partly or 
completely discarded. There is no objection to giving 



DIET DURING SECOND YEAR. 307 

milk in a bottle once or twice daily until the child is 
three or four years old, if it prefers this way of taking it. 
A bottle holding ten or twelve ounces may be used, and 
the nipple will at least insure its being taken slowly. 
Some young children will take milk in this manner while 
utterly refusing it when offered in a cup. By using tact 
in the method of giving food and employing some variety 
in the dietary, the baby can usually be nourished success- 
fully. New articles must, however, be started slowly and 
gradually; the danger is in giving too much, both in 
quantity and variety, in the period between babyhood 
and early childhood. 



PART IV. 



CHAPTER XXVIII 
GROWTH AND DEVELOPMENT OF INFANTS. 

173. The best gauge of good feeding and nutrition will 
be a proper rate of growth and development. While ab- 
solute rules cannot be given for every case, there is a nor- 
mal ratio that, within certain limits, should be attained 
by the average infant. The exact ratio for each individ- 
ual is governed by hereditary influences determining the 
general framework of the body at birth, as well as by the 
kind of food available after birth. Some infants are born 
with very small bones, perhaps in this respect resembling 
one or both parents. The birth weight of such an infant, 
as well as that attained later, will be less than that of a 
baby having a large bony framework. Different races, as 
well as families, show considerable variation in this re- 
spect, within the limits of health. Needless alarm is 
sometimes excited if the physician or mother simply con- 
siders averages that are taken from a different class or 
community that do not apply particularly to the baby 
under consideration. In every case, however, the ex- 
tremely rapid growth of the infant after birth makes a 
careful observation of all the phenomena connected there- 
with not only interesting but important. 

174. Of all the factors to be thus considered, weight is 
the most important. It is practically the most valuable, 
as showing whether the food has the proper nutritive in- 



3 i2 INFANT FEEDING. 

gredients and whether digestion and assimilation are well 
performing their functions. From birth on, the weight 
of the body must be taken and recorded at regular inter- 
vals, preferably once a week (128). 

If food is being changed to try and correct a station- 
ary or losing weight, the scales may be used every two or 
three days, but it must always be remembered that babies 
are apt to gain irregularly at short intervals. One day 
the infant may show a gain of an ounce and the next day 




Fig. S4.— Grocer's Scales for Weighing Infants and Children. 

a quarter of that amount, while doing perfectly well. 
Again, the weight may remain stationary for a day or so, 
and then jump up two ounces in twenty-four hours. The 
same person should do the weighing on the same scales, 
to insure uniformity. A grocer's scales, weighing frac- 
tions of an ounce, or those specially constructed for in- 
fants, may be used. 

The following chart, devised by Carr, is convenient to 
record the weighings. After weighing, put a dot where 
the line from the infant's weight crosses the line from its 



GROWTH OF INFANTS. 



3i3 



age in weeks. By connecting the dots, the weignt line is 
the result. 



V/EIGHT IN GRAMS. 









1 \ 




I = 




| 










1 ! 


i 


1 




c> S ^ ^ £: <5 


"p 


| 1 












II 


j-+m 










. 




. 1 . • ' I 1 IN || | i 


S 

r 

s 
a 


" 




' 


. 


... 




















... 




.::.. -■: — — : -±:.:=; 


CO ~" 

z s 














" 




— 


— 








: 


- 


III ! 

■ . : 1 ' 1 | 1 | i 

\ 


X 




— 


















'"'-- 








r " 





•SaNOOd Nl J.HPI3M 

The infant should, of course, always be weighed in 
the same clothing, that can then be easily deducted from 
the total. 



3i4 



INFANT FEEDING. 



At birth the male infant usually weighs a little more 
than the female. In a series measured for the author, 
the males weighed from six to eight pounds, and the 
females from five and a half to seven pounds. During 
the first two months, it is considered by Rotch that the 
daily average gain should not fall below 20 gm. (two-thirds 
of an ounce). He gives the following table indicating a 
healthy increase in weight : 



Age. 


Weight. 


Average Gain Per 
Dav. 


Grams. 


Pounds. 


Grams. 


Ounces. 


At birth 


3,000-4,000 


6.6-8.8 


20-30 
I0-20 








From five months to twelve months . . 



The infant should double its birth weight at five or 
six months, and treble it at fifteen or sixteen months. 

175. The length of the new-born baby is slightly greater 
in the male than in the female. In a number measured 
for the author, the males averaged 50 cm. (19.6 inches), 
and the females 48.6 cm. (19.1 inches). 

Growth in length is extremely rapid during infancy, 
especially in the earlier months. It is most rapid during 
the first month, a little less so during the second, the rate 
of rapidity decreasing with each month. The following 
figures referring to growth in length are taken from 
Rotch: 

The average increase for the first month is about 4.5 
cm. (i}{ inches); for the second month about 3.0 cm. 
(i l A inches); for the third to the fifteenth month about 
1 to 1.5 cm. (}4 to }i inch); for the first year about 20 
cm. (8 inches); for the second year about 9 cm. (3^ 



GROWTH OF INFANTS. 315 

inches); for the third year about 7.4 cm. (3 inches); for 
the fourth and fifth years about 6.4 cm. {2% inches) ; for 
the fifth to the fourteenth year about 6 cm. (2}i inches). 

176. One of the best indices of proper nutrition is an 
easy and timely cutting of the first teeth. This process 
starts early in intra-uterine life and should be completed 
at the end of infancy. At birth, although nothing but 
smooth gums are to be seen, the alveolar processes enclose 
the twenty temporary or milk teeth in embryo. When 
beginning to come through the gums, they usually ap- 
pear in groups. The first to be cut are apt to be one or 




Fig. 86.— Diagram Showing Average Months for Cutting Teeth. 

both of the middle lower incisors, at the sixth or seventh 
month. The rest are gradually evolved, usually in the 
following order: upper central incisors, upper lateral inci- 
sors, four anterior molars, four canines, and finally the 
four posterior molars. The first dentition should be 
completed by the end of infancy at the age of two and a 
half years. 

There is always some variation, within the limits of 
health, as to the exact time of the evolution of the teeth. 
It may be said, however, that much delay in teething is 
an evidence of faulty nutrition or constitutional disease, 
such as rickets. Such delay must hence call for a care- 



ii6 



INFANT FEEDING. 



ful investigation of the food, both as to proper ingredients 
and adaptability for the infant's digestion. 




Fig. 87— One Day Old. 



177- A few pictures of normally developing infants will 
be shown, as affording a guide to the eye in recognizing 
what may be expected at various ages. Care has been 




Fig. 88.— Three Months. 



taken to get these pictures in natural positions and post- 
ures. Just after birth, the trunk, arms, legs, and head 



GROWTH OF INFANTS. 



31/ 



have peculiar conformations. The body is of an elliptical 
shape, with the widest part at about the centre over the 




liver, in the region of the lower ribs. The two ends of 
the ellipse, represented by the thorax and pelvis, are small 




Fig. 90.— Six Mom hs. 



and not well developed. The arms are stronger and bet- 
ter developed than the legs. During intra-uterine life the 






3i8 



INFANT FEEDING. 



baby is placed in a sort of squatting position, with the 
legs drawn up and curled inward. This explains why the 







-Twelve Months. 



young infant's legs are not straight, but have a decided 
bowing in of the tibia and fibula. The soles of the feet 




Fig. 92.— Twelve Months. 



also tend to face inward. The head is larger than the 
chest at this time, ,with a very short neck, and the baby 



GROWTH OF INFANTS. 



319 



assumes a position of general flexion. The peculiarities 
of early infantile shape and position are well shown in the 
illustrations. 

For a time after birth the greatest relative strength is 
shown in the hands and arms, as one can easily verify by 
allowing the infant to grasp a finger and then trying to 
pull it away. At about three months the muscles of the 




Fig. 93. — Fourteen Months. 



neck have developed sufficiently to allow the infant to try 
and hold up its head in an uncertain way. At the sev- 
enth or eighth month the muscles of the back have become 
strengthened so that the baby can sit up, and shortly after 
this the infant maybe allowed to creep. There should be 
given free play for the muscles of the arms and legs from 
the first, as muscular and bony development is thus 



320 



INFANT FEEDING. 




bUj. 95. — Eighteen Months 



GROWTH OF INFANTS. 



321 























it* 1 








:..•■ '• 






' ^ 


iv -^m 


r^ *> 




; '"' 




: : ^ 


Il.u.^* 













Fig. 96.— Eighteen Months. 




Fig. 97.— Two Years. 



21 



INFANT FEEDING. 




Fig. 98.-Rontgcn Picture oi an i 



encouraged. The bones of the legs thus grow and 
straighten out, but this will be interfered with if the baby 
is made to sustain the weight of the body too soon. 



GROWTH OF INFANTS. 323 

The average baby should not be encouraged to stand 
before the twelfth month ; efforts to walk may be begun 
from then on to the fifteenth and sixteenth month. 
When walking has been established the legs should be 
straight. The chest develops rapidly, with enlargement 
of the pectoral and shoulder muscles, and its circumfer- 
ence usually equals that of the head by the end of the 
first year. The Rontgen picture taken for the author by 
Dr. W. J. Morton shows the undeveloped condition of 
the bones of a young infant, and the importance of giving 
proper nutriment to build up these and other tissues. 



CHAPTER XXIX 

Methods and Results of Measuring Normal Infants. 

178. In order to have additional and new data relative 
to the growth of healthy infants, a series of careful meas- 
urements were made for the author by Dr. A. Hrdlicka, 
the anthropologist, assisted by Dr. Pisek. Two hundred 
infants were thus examined, and the tables and deduc- 
tions given below are obtained solely from this work. 
By having one man alone, and he an expert, make all the 
measurements with instruments of precision, it is be- 
lieved that reliable statistics have been obtained. At the 
same time only a few measurements that would throw 
light upon the general development of the infant were 
taken, so that any careful person can make similar measure- 
ments for comparative purposes. Healthy children from 
the nurseries of the New York Infant Asylum, the New 
York Foundling Asylum, and the Mount Vernon Infant 
Asylum were used, and the author extends thanks to 
these institutions for the courtesies extended. The ages 
of the infants varied from the new-born of a few hours to 
those of two years. There were ninety-six males and one 
hundred and four females. Well-developed children only 
were selected, the majority being on the breast and the 
remainder bottle-fed but in every instance doing well on 
its feeding. Any child who had been in hospital or 
showed signs of marasmus, rickets, or other constitu- 



METHODS OF MEASURING INFANTS. 



325 



tional disease was rejected, as the purpose was to obtain 
the measurements of the average healthy child at various 




Fig. yy. — French Calipers. 



ages. The instruments used for this work were a French 
non-stretchable tape for the circumferences, a pair of 
French calipers for the diameters, and a measuring board 



326 INFANT FEEDING. 

to determine the length. The board was designed to 
give true results and obviate the inaccuracies obtained in 
the usual forms of apparatus employed. In the ordinary 
forms the pelvis can be tilted, as only one foot is pro- 
vided for by the construction. 

The measuring board here used consists simply of a 
plain board about forty inches long by eleven inches 
wide, with a firm upright headpiece attached at one end 
and a sliding footboard at the other end. 

On the board two engine-ruled metric scales are 
placed parallel to each other. Care must be taken to 




tt t ^ c 



Fig. i oo- Measuring Board. A, Sliding foot-board ; B, headpiece ; C, metre scales. 

have the child's head well up against the headpiece and 
held there by an assistant, while the measurer presses 
down both knees, pushing the footboard close to the 
plantar surfaces of the feet. The infant is then removed 
and a reading made on the scale. 

The following measurements were taken : 
f Circumference, 



Head - Antero-posterior diameter, 



Lateral maximum diameter 
Chest — circumference. 
Length of body. 
Weight of body. 



METHODS OF MEASURING INFANTS. 327 

The relation of the weight to the length, the relation 
of the circumference of the head to the length, and the 
relation of circumference of the chest to the length were 
then calculated. Tables were next prepared dividing the 
results according to ages in weeks. The resume given 
below has been reduced to ages in months for the pur- 
pose of brevity and simplicity. The largest and smallest 
measurement of each group is indicated in the metric 
system, and in inches, and pounds and ounces. 

If we study the table, we find that the males weigh 
more than the females throughout the period of twenty- 
four months. In length the males also exceed the fe- 
males, but the difference is slight up to the twelfth month, 
when the males show a greater divergence. This is well 
shown in the relation of weight to length in the last col- 
umn. The circumference of the head is greater than the 
circumference of the chest at birth, and remains so up to 
the middle of the first year, when they begin to approxi- 
mate in size ; at the end of the first year the chest grows 
larger than the head. The females, it will be noticed, 
begin to show greater circumference of chest to head at 
the tenth month, which remains so throughout. The 
columns giving the relationship which exists between the 
circumference of the head and the length of body, and 
that of the head to the chest, will be an aid in recog- 
nizing abnormal cases, such as rickets or hydroceph- 
alus. 

The relations spoken of above are obtained from the 
measurements as follows : 

1. Weight to the length. 

Multiply grams of weight by 100 and divide by centi- 



3 28 INFANT FEEDING. 

metres of length. Example: Weight 2,778 gm. X 100 -f- 
50 cm. length = 55.6, relation of weight to length. 

2. Relation of circumference of head to length of body. 

Table of Measurements (Males). 



Males. 
Age 


Weight 


Le 


lgth 


Circ. of head 


Circ. of chest 


Ratit 


s of measurements 


! 


u 


= 1 
6 1 


& 


is 
si 


6 


S3 


a 


|j| 


lit 


"3 S.a 


* - 


1 daj--l month 


to 3912 


6 15 
8 9 


50. 
55.3 


19.6 
21 8 


35.1 

38.3 


13.8 
15.1 


32. 
36.7 


12.6 
14.4 


91.1 
95.8 


65.8 
72.1 


63. 
71.6 


54.9 

76.7 


1 - 2 months 


3374 
to 5216 


11 7 


52.5 
59.6 


20.7 
23.5 


36.6 
39.5 


14.4 

15.5 


35. 
38. 


13.8 
15. 


95.6 
96.3 


66.1 
71.6 


63.8 
68.3 


62.2 
87.6 


2-3 


3459 
to 5528 


7 9 
12 2 


55.9 
60.8 


22. 
23.9 


38.9 
41.2 


15.3 
16.2 


34.9 
41.2 


13.7 
16.2 


89.7 
100. 


67.1 
70.8 


61.7 
69.5 


59.8 
92.1 


3-4 « 


5018 
to 6801 


11 
14 15 


59.1 
63.1 


23.3 
24.8 


40.2 
44. 


15.8 
17.3 


37.5 
42. 


14.8 
16.5 


93.3 
95.5 


64.9 
70.7 


60.4 
69. 


82.1 

107.8 


4-5 " 


6152 
to 7201 


13 8 
15 13 


66.2 
66.3 


26. 
26.1 


41.3 
42 2 


16.3 
16.6 


11.1 

43.2 


10.3 
17. 


99.5 
102.4 


62.3 
63.7 


62.1 
65.2 


92.9 
108.6 


5-6 


4990 
to 7796 


11 9 
17 2 


59. 
68.5 


23. 
27. 


40.5 
43.9 


16. 
17.3 


39.9 

43.3 


15.7 


98.5 
98.9 


64.1 
69. 


63.2 
67 9 


83.7 
113.8 


6-7 " 


5698 
to 7995 


12 8 
18 


64.8 

68.7 


25.5 

27. 


43.2 
45.3 


17.8 


41.2 
45.2 


16.2 


95.4 
99.8 


65.3 
67.5 


62.6 
68.2 


87.9 
119.1 


7-8 


4536 
to 7924 


9 15 
17 6 


59.1 
70.8 


23.3 
27.9 


40. 
44.4 


15.7 
17.5 


38. 
44.9 


15. 


95. 
102. 


62.7 
69.1 


63.4 
64.3 


76.8 
111.9 


8-9 


6804 
to 8661 


14 15 
19 


66.1 
70.8 


26.0 
27.9 


44.7 

47.3 


17.6 
18.6 


40.8 
47.1 


16.1 
18.5 


91.3 

99.6 


63.3 
69.2 


59. i 
69. 


101.5 
122.3 


9-10 " 


6662 
to 8732 


15 1 
19 2 


64.8 


25.5 

28. 


42.9 
46.3 


16.9 
18.2 


42.3 
46.1 


16.7 
18.2 


98.6 
99.6 


65.1 
68.3 


64.8 
66. 


102.5 
122.8 


10-11 « 


to 8565 


14 14 

18 12 


61.7 
79. 


25.5 
31. 


44.8 

45.5 


17.6 
17.9 


39.2 
45.3 


15.4 

17.8 


99.6 


63.6 
69.5 


56.3 
68. 


104.7 
119.9 


11 -12 " 


6634 
to 8392 


14 9 

18 3 


66.1 
69.8 


20. 
27.5 


44.7 
45.3 


17.6 


43.4 
45.1 


17.8 


97.1 
99.5 


64.9 
67.3 


64.5 

68.2 


99.4 
120.2 


12-13 <• 


7938 
to 9157 


17 8 
20 1 


69.4 
71.5 


28.2 


45.6 
47. 


18. 
18.5 


42.1 
48.3 


16.5 
19. 


92.3 
102.7 


63.8 
66.6 


60.7 
67.3 


114.4 
1281 


13 - 14 « 


7258 
to 8874 


15 15 
19 7 


69.6 
76. 


27.4 
29.9 


46. 
48.3 


18.1 

19. 


42.1 
47.7 


16.5 
18.8 


91.5 
98.8 


63.4 
67.7 


60.5 
64.3 


104.3 
121.1 


20-21 c. 


10093 


22 2 


75.7 


29.8 


48.1 


18 9 


50.1 


19.7 


104.2 


63.5 


66.2 


133.3 


22-23 n 


8108 
to 11113 


18 5 
24 6 


72.2 


28.4 
32.8 


45. 
47.9 


18.9 


43.8 

51.7 


17.2 
20.4 


97.3 
107.9 


57.4 
62.3 


60.6 
61.9 


112.3 
133.3 


23-24 r. 


10886 
to 11113 


23 14 
21 6 


76.4 
82. 


30.1 
32.3 


47.6 

49. 


18.7 
19.3 


50.7 
50.8 


19.9 
20. 


106.5 
103.7 


59.7 
62.3 


61.9 
66.4 


132.8 
145.5 


2-*3 years 


10830 


23 12 


79.8 


31.4 


49. 


19.3 


49.9 


19 6 


101.8 


61.4 


62.5 


135.7 



Multiply circumference of head by 100 and divide by 
length of body. Example: 35.1 X 100 -r- 50 = 70.2. 

3. Relation of circumference of chest to length of 
body. 



METHODS OF MEASURING INFANTS. 



329 



Multiply circumference of chest by 100 and divide by 
length of body. Example: 32 X 100 -r- 50 = 64.0. 

4. Relation of circumference of head to circumference 
of chest. 

Table of Measurements (Females). 



Females 

Age 


Weight 


Length 


Circ. of head 


Circ. of chest 


Ratios of measurements ■ 


I 


S3 


II 


d 


of 
& 1 


a 


II 


d 


g|l 


o!j 


||J 


H 


1 day-1 month 


2580 
to 3601 


5 10 

7 14 


48.6 

52.8 


19 1 
20.8 


33.4 
37.1 


13.1 
11.6 


30. 
35.9 


11.8 
14.1 


89.8 
96.8 


66.1 
72.2 


61.7 
69.8 


53.1 

71.7 


1-2 months 


3373 
to 4678 


7 6 
10 4 


52. 
59.3 


20.5 
23.3 


35.3 
39. 


13.9 
15.4 


32.8 
39. 


12.9 
15.4 


95.7 
100. 


63.6 
73.2 


61.5 

66.8 


64.9 
78.9 


2-3 " 


3799 
to 6010 


8 5 
13 3 


54.6 
62. 


21.5 
24.4 


37.3 
41.1 


14.8 
16.2 


34.8 
39.8 


13.7 
15.7 


93.3 
96.8 


65.8 
70.1 


59.7 
68.9 


67. 
10L 


3-4 


4281 
to 5698 


9 6 
12 8 


56.3 
61.9 


22.2 
21.4 


39. 

42.1 


15.4 
16.6 


36.2 
44. 


14.3 
17.3 


92.8 
104.5 


64.2 
72.4 


61.8 
71.7 


75.7 
97.7 


4-5 


4494 
to 5585 


9 14 
12 5 


59.9 
62.3 


23.6 
24.5 


40.2 
41.3 


15.8 
16.3 


37.1 
41.7 


14.6 
16.4 


92.3 
100.9 


65.7 
67. 


60.5 
66.9 


75. 
89.6 


5-6 


5500 
to 6549 


12 2 
14 6 


61.9 
66.1 


24.4 

26. 


41.7 
44.6 


16.4 
17.6 


38.6 
43.2 


15.2 
17. 


92.5 
96.8 


65.3 
67.9 


59. 
66.1 


99.7 


6-7 


6634 
to 7768 


14 9 
17 1 


63.9 
66. 


25.2 
26. 


43.1 
43.8 


17. 
17.2 


39.8 
43.1 


15.7 


92.3 
98.4 


65.6 
67.6 


62.3 
65.4 


103.8 
117.7 


7-8 " 


6577 
to 8760 


14 7 
19 3 


63.2 
69.9 


24.9 
27.5 


42.7 
44. 


16.8 
17.3 


42.1 

46.8 


16.6 
18.4 


98.6 
106.4 


63. 
68.8 


66.6 

70.7 


104.1 
125.3 


8-9 " 


7030 
to 7853 


15 7 
17 3 


65.8 
68.8 


25.9 
27.1 


42. i 
46.2 


16.6 

18.2 


41.2 
43.7 


16.2 
17.2 


97.8 
94.6 


63.8 

67.2 


61.1 
66.2 


104.6 
115.5 


9-10 " 


5557 
to 6804 


12 3 
14 15 


62.9 
64.4 


24.8 
25.4 


42.4 
42.8 


16.7 
16.9 


39.3 
40.8 


15.5 
16.1 


92.7 
95.3 


66.5 
67.2 


61. 
64.8 


88.3 
105.6 


10-11 « 


5188 
to 9044 


11 6 

19 13 


64.4 
69.8 


25.4 
27.5 


43.6 
45.9 


17.2 
18.1 


42.5 
48. 


16 7 
19. 


97.4 
104.6 


64.8 
70.8 


63.4 
69.1 


80.6 
129.5 


11-12 " 


to 9299 


15 3 
20 6 


63.7 
71.3 


25.1 
28.1 


43.7 
46.3 


17.2 
18.2 


42.8 
48.3 


16.9 
19. 


97.9 
104.3 


63.2 
69.2 


62.1 
72.4 


107. 
134.8 


12-13 " 


6152 

to 8590 


13 8 
18 13 


62.5 
71.1 


25.6 
28. 


41.1 
44. 


16.2 
17.3 


43.1 
48.1 


17. 
18.9 


104.8 
109.3 


61.7 
65.8 


67.7 
68.9 


98.4 
120.8 


13-14 " 


7655 
to 9526 


16 14 
20 14 . 


70.5 
72.6 


27.7 
28.6 


45.3 
48.1 


17.8 
18.9 


45.1 
49.4 


17.8 
19. 


99.5 
102.7 


63. 
66.9 


63.7 
70. 


108.6 
131.2 


16-17 " 


7513 
to 8080 


16 8 

17 11 


69.1 
72.4 


27.2 
28.5 


44.7 
45.1 


17.6 
17.8 


45.2 
47.2 


17.8 
18.6 


101.1 
104.6 


61.7 
65.3 


62.4 
68.3 


103.8 
116.9 


17-18 


7626 


16 12 


71.4 


28.1 


44.3 


17.4 


43.9 


17.3 


99.1 


62. 


61.1 


106.8 


19-20 " 


8335 


18 3 


73.9 


29.1 


46.3 


18.2 


46.6 


18.3 


100.7 


62.7 


63.1 . 


112.8 


23-24 " 


8789 


19 4 


77.5 


30.5 


45.6 


18. 


47.1 


18.5 


103.3 


58.8 


60.8 


113.4 



Multiply circumference of head by 100 and divide by 

circumference of chest. Example: 32 X 100 -f- 35.1 = 91.1. 

While infants at birth may vary widely in size, each 



330 



INFANT FEEDING 



individual should develop in proper proportion, the vari- 
ous parts of the body having a symmetrical relationship 
to one another. These tables will thus be found useful 
in estimating a divergence from the normal average in 
any given child. Thus, for example, we have a male in- 





WEIGHT 
7LBS.12 0Z. 




WEIGHT 
15.4 LBS. 



WEIGHT 
! LBS. 9 OZ. 



12 MOS. 
Fig. ioi. — Diagrams of Relative Measurements Constructed from Table. 

fant of five and a half months that comes for examination 
and to have its feedings regulated. It is determined that 
this infant should not weigh less than 4,990 gm., the 
length should be between 59.0 and 68.5 cm., the circum- 
ference of the head should average about 42.0 cm., the 



METHODS OF MEASURING INFANTS. 



33i 



chest slightly below this figure, and the proportion of the 
length to the weight should not fall below 98.8. 

The diagrams (Figs. 101 and 102) done in scale will show 
to the eye the averages of the table at various ages. 




WEIGHT 
22 LBS. 2 OZ. 




WEIGHT 
24 LBS. 



24 MOS. 
1 2. -Diagrams of Realative Measurements Constructed from Table. 



CHAPTER XXX. 
Growth of Head. 

179* In the human being the brain assumes overmas- 
tering importance in the scheme of evolution, hence its 
proper growth and development assumes relatively more 
importance than that of other parts of the body. The 
extremely rapid evolution of the brain during infancy, 
and the fact that the future efficiency and well-being of the 
individual depend so largely upon its normal and healthy 
growth, render a study of the infantile head of great 
interest. As the skull is fairly representative of the 
brain during the years of its first development, measure- 
ments taken during infancy are more instructive as to 
brain size and development than those taken in later 
years. The skull changes considerably in its proportions 
during the first three years of life, and then more slowly 
up to the end of the seventh year, when it has very nearly 
attained its full size. Ninety-eight cases, from birth up 
to two years, were carefully measured by the author, and 
the results are incorporated in the following table. 

Some of these figures are very slightly under similar 
measurements made by Dr. Hrdlicka in his series upon 
the general growth of infants. This is explained by the 
fact that the author made his studies upon hospital cases, 
where the subcutaneous tissue over the skull is apt to be 
somewhat atrophied. The bony configuration of the 



GROWTH OF HEAD. 



333 



•S3SB0 XIS 'SJBsA 

oa\j o] 'sqjuoui 

U 3 3 } q 2 1 3 UICU J 


<M 1 * 


VO M VO CC 
CO m" Oo' C 


c 


■6 -c 

1 1 

u 


it 

11 




vd 




■JSB3jq 
UO OMJ 'S3SED 
3q3ig[ -(SAisnpui) 
sqjuoui ubsjqSi's 

OJ 3A[3«1 UIOJjJ 


6 lO A M «" 0* (>■ OO' CT> MM II VO 

y-rvgmMM « « II 

M MO 


•S3SB3 xis 'sqjuoui 

3AJ3MJ pUB U3A3J3 


S 4 « 0* N* M vo OO t^. CO ci || vd 

a 1 ff 


•JSB3jq UO 

oaij 'sssbo jqSp 
'sqjuoui usj puB siiijvj 


voncoMOvo vo vo oKt^.0 1 
g « « oo m m vd vd vd m w fp vd 

«- JO « - M « « 1 


•jSB3jq uo suo 
S3SB3 sau 'sqjuoui 

jqSp pUB U3A3g 


rOMOvOOr^ vo O VO OJ m co 


•JSE3-iq uo 

auo 'sas-BO 3uiu 

'Sq^UOUI XIS pUB 3AIj[ 


. o> m o oo m o oo 


vo 


SoOMVOChO^o r. 
CO £ « M IN 


i vn co co jj m 

III 


";sB3jq 

U O 3 3 t q J 'S3SB0 
3uiu ' s q ] u o ui 
jnoj puB 33-iqj, 


in oo' oo o m \o co oo co vd « 

g oo" d "-> d d iA ■*• in co co f[~ ^T 

<j m IT " M " N N m V g w 

si J 


•jSBSjq 

UO U3A3S 'S3SB3 

U33jqSi3 'sqjuoui 
33jqj 0} 3UO UIOJJ 


in in vo m co co m in m vo co in 

, * t^ «n *f- o ov m CO co ^- co ! vo 

H d> 1 N 


•jSESjq 

UO U33jq2l3 'S3SB0 
AjU3A\J 'qjUOUI 3UO 
OJ JJ33M 3UO UKUjI 

•jSB3jq uo \ye S3SB3 
3Uiu 'qjJiq uiOJj 
•JJ33AV 3lio J3pUfl 




ocoinooo m m in o in o 
„-OOOcoovco ov 1-t~t-.ro 
A in d> co d- oo' 4 « co ■*■ co II vo 
U co vo n NN mio 

« I CO 

o- « 


VO 

. n-*co«-»-vo m Q S dv •» 
_• t~ ->r co « ov 5 vo_ r~. ov 
jj -«■ tC « d co' ■«■ tf «" ■>)- co li -vr 




1 J 1 

< V 


Naso bregmatic arc 

Bregmato-lambdoid arc . . 

Lambdo-occipital arc 

Binauricular arc (through 


A 


.5 

CI 

11 


1 j 

w O 

c "C 

g 8 1 

1 1 J 


u 


c 

[5 





334 



INFANT FEEDING. 



skull, produced by the growing brain, would, however, 
not be affected by this circumstance. No distinction was 
made between the sexes. The circumference was taken 
by passing the tape horizontally around the head, passing 
over the glabella and a point just above the external 
occipital protuberance. When this is procured the fol- 
lowing data will give a very rough approximation of the 
volume: x : circumference : : 1350 : 50. Thus, if the 
circumference is 42 cm., the approximate volume will be 



JSrep/na 



f/a&f/a 




'-ZamScfa 






Fig. 103.— Outline of the Skull. 



1 1 34 c.c. The naso-occipital arc was measured from the 
glabella to the external occipital protuberance. Before 
removing the tape, the three arcs composing the naso- 
occipital were read off — namely, the naso-bregmatic, the 
bregmato-lambdoid, and the lambdo-occipital arcs. These 
points are shown in the following outline of a skull, and 
are easily recognized in the infant. 

The bregma and lambda were previously marked with 
an aniline pencil, so that the readings on the tape at 



GROWTH OF HEAD. 



335 



these points could be readily made. Where the anterior 
fontanel was open, a line in continuation of the frontal 
sutures was marked. The binauricular arcs were meas- 
ured, in both cases, from the anterior rim of the meatus, 
and passing the tape respectively over the bregma and 
lambda. When the anterior fontanel was open, the 
anteroposterior and lateral diameters were taken. The 
cephalic, or length-breadth index, was measured by cali- 
pers, which were applied at the greatest biparietal and 
antero-posterior diameters. The formula for obtaining 
this index is as follows: Length : Breadth : : ioo : x. All 
cephalic indices falling below j8 are classed as dolicho- 
cephalic; from yS to 80, mesocephalic ; and above 80, 
brachycephalic. The facial length was measured from 
the root of the nose to the extremity of the chin, and, in 
the absence of the teeth, falls relatively considerably be 
low the adult. A configuration of the skull in each case 
was taken by carefully applying a strip of sheet-lead hori- 
zontally around it, just above the ear, the free ends always 
being on the right side for the purpose of uniformity. 
The tracing was then put upon a chart by running the 
point of a sharp pencil just inside the lea. 1 . It is well to 
mark the centre of the lead in front, so as to be able ap- 
proximately to draw a median line through the configura- 
tion and thus detect asymmetry. It is not contended 
that this is an absolutely accurate method of obtaining a 
configuration of the skull, as the metal is so yielding that 
there is a possibility of its springing somewhat in trans- 
ferring it from the skull to the chart. With care, how- 
ever, it is fairly accurate, and will exhibit the general 
pushing out of the soft skull by the growth of the brain, 



336 



INFANT FEEDING. 




Fig. 104.— Fetal Skull, Between 
Three and Four Months. 



and any form of asymmetry that is at all marked. The 
following configurations, taken from the list, are fairly 
typical of the usual shaping of the 
skull, in a horizontal plane, at 
various ages during its most rapid 
growth. 

180. The fetal skull is very 
small, and oval at an early stage, 
as both the sensori-motor and in- 
tellectual centres have not yet be- 
gun to grow. The former begins 
to develop later in intra-uterine 
life, and the latter the last of all. 
This is beautifully shown in the configurations of the two 
fetal skulls. The first shows an oval, undeveloped brain, 
while the second exhibits the forcing out of the parietal 
bosses by the rapid evo- 
lution of the sensori- 
motor area of the brain, 
while the front of the 
skull appears station- 
ary, from the size of the 
configuration. After 
birth and with increase 
in the age of the in- 
fants, there is noted a 
gradual and steady 
enlargement of the 
great circumference of 

the Skull, and, from Fig. 105.— Fetal Skull, Seven Months, Showing the 
,1 • r •, ,« ,i Forcing Out of the Parietal Bosses by the Develop- 

tniS, 01 ltS estimated m ent of the Sensori-motor Area of Brain. 




GROWTH OF HEAD. 



337 



volume. The naso-occipital arc likewise increases at 
about the same general rate as the great circum- 
ference. In comparing the naso-occipital arc with the 
great circumference, there is an increasing difference 




Fig. 106. — Horizontal Configuration of New-Horn Baby (Female), Small, but Sym- 
metrically Developed. 
Measurements. 

Diameters of anterior fontanel — antero-poste- 



Great circumference, 31 cm. 
Naso-occipital arc, 22 cm. 
Naso-brtgmatic arc, 9 cm. 
Bregmato-Iambdoid arc, 9 cm. 
Lambdo-occipital arc, 4 cm. 
Hinauricular arc (through bregma), 22 cm 
Uinauricular arc (through lambda), 24 cm 
22 



rior, 5.5 cm. ; lateral, 5 cm. 
Cephalic index, 8-10. 
Facial length, 5 cm. 
Circumference of chest, 26.5 cm. 
Length of body, 46.5 cm 
Weight of body, 5 pounds.. 



338 INFANT FEEDING. 

as the infants grow older. Thus, in the table, the differ- 
ence under one week is 12.39 cm., while at two years it is 
14.58 cm. The naso-bregmatic and bregmato-lambdoid 
arcs are very similar in the series, but after seven months 
the former arc becomes slightly larger from the develop- 
ment of the frontal lobes of the brain. While the parie- 
tal bosses cover the sensory and, to a certain extent, the 
motor cortical areas, the bones of the forehead will indi- 
cate by their shape the stage of development of the fron- 
tal lobes, the foundation of the intellectual portion of the 
brain. Although no intellectual growth can be said to 
take place under two years, there should be an active 
evolution of the front of the brain, with increase of the 
perceptions. The first rapid growth of the brain after 
birth is more in bulk than in size and complexity of the 
convolutions. Hence in early infancy the various corti- 
cal centres have but a slight development and function. 
With proper evolution, the convolutions grow and are 
arranged in functional groups, which groups, by their 
growth, alter and modify the shape of the infantile skull. 
If the skull is small or improperly shaped in any part, the 
brain in such an area is imperfectly developing. A cer- 
tain amount of asymmetry, however, is found in all skulls, 
as in the other members of the body, and will be seen in 
the tracings previously shown. Older children some- 
times exhibit a compensatory deformity from a too early 
closure of some of the sutures of the infantile skull, that 
does not allow the expanding brain to develop in a sym- 
metrical manner. Such cases are not apt to exhibit ab- 
normality of brain function. The brain has simply pushed 
out at the point of least resistance. 



GROWTH OF HEAD 



339 



Fig. to7.— Horizontal Confignrati 

Great circumference, 44 cm. 
Naso-occipital arc, 29 cm. 
Naso-bregmatic arc, 11.5 cm. 
Bregmato-lambdoid arc, 12.5 cm. 
Lambdo occipital arc, 5 cm. 
Binauricular arc (through bregma), a6 cm. 
Binauricular arc (through lambda), 26.5 cm. 



(F 



Ted 011 breast. 



of Baby of Ten Month: 

\1, ,, :<> ,lil,->lts. 

Diameters of anterior fontanel— antero-posterior, 

< in. ; lateral, 1 cm. 
Cephalic index, 11-15. 
Facial length, 6 cm. 
Circumference of chest, 43.5 cm. 
Li Miii <>f body, 68 cm. 
w. 1. hi -1 body, 14 1 is. 1 oz. 



340 INFANT FEEDING. 

181. The fontanel is usually completely closed from 
the eighteenth to the twentieth month. As will be seen 
from the table, the closing is rather slow until the twelfth 
month, when it proceeds much more rapidly. In all the 
cases examined, the fontanel had closed by the eigh- 
teenth month. Where the fontanel remains widely 
open with the increased age of the infant, there will 
always be marked symptoms of rickets elsewhere. Thus, 
in the case of a male infant, aged ten months, with both 
diameters 5 cm., the configuration showed a markedly 
rickety head, and the notes gave other symptoms of the 
disease. 

The facial length increases slowly in infants, as would be 
expected from the absence of teeth. In older babies, when 
dentition is completed, the length increases more rapidly. 

The importance of good nutrition in relation to brain 
growth will be appreciated from the fact that, in the cases 
examined by the author, the skulls of breast-fed babies 
presented slightly larger measurements than those artifi- 
cially fed, especially when the latter were not digesting 
and assimilating their food well. 

The principle of biology, that the development of the 
individual reproduces, on a small scale, the development 
of the race, is well shown in the infant's brain. The 
higher centres and the centres of association are devel- 
oped late in the child. These are likewise the last ac- 
quirements of the race. The lower and more funda- 
mental animal traits are transmitted by inheritance more 
than the higher ones. Good nutrition and good training 
are both required to develop the higher functions of the 
brain in a satisfactory manner. 



34i 



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Physiology of the Domestic Animals. R. Meade Smith. Philadelphia, 
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The Food of Nestling Birds. S. D. Judd. U. S. Dept. Agr. Year Book, 
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Text-Book of Physiological Chemistry. Olof Hammarsten, translated by 
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Text-Book of Physiological Botany. G. L. Goodale. New York and Chi- 
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The Soluble Ferments and Fermentation. J. Reynolds Green. Cam- 
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Enzymes and their Applications. Jean Effront, translated by Samuel C. 
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Experiments on the Metabolism of Matter and Energy in the Human 
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The Effect of Severe and Prolonged Muscular Work on Food Consump- 
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Nutrition Investigations at the California Agricultural Experiment Sta- 
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Nutrition Investigations among Fruitarians and Chinese at the California 
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A Report of Investigations on the Digestibility and Nutritive Value of 
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Studies in Bread and Bread-making. Harry Snyder and L. A. Voorhees. 
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Feeds and Feeding. W. A. Henry. Madison, Wis., 1902. 

The Feeding of Animals. W. H. Jordan. New York, 1903. 

Principles of Nutrition and Nutritive Value of Food. W. O. Atwater. 
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Foods: Nutritive Value and Cost. W. O. Atwater. Washington, 1S94. 

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Practical Dietetics. W. Oilman Thompson. New York, 1901. 

Meals: Composition and Cooking. Charles D. Woods. Washington, 
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342 REFERENCES. 

Food and Food Adulterants (Preserved Meats). Bull. 13. Pt. 10, Div. 
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Food and Food Adulterants (Cereals). Bull. 13, Pt. 9, Div. Chemistry, 
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Cereal Breakfast Foods. Bull. 55, Maine Agr. Exp. Station. 

Beans, Peas, and other Legumes as Food. Mary Hinman Abel. Wash- 
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Value of Potatoes as Food. C. F. Langworthy. U. S. Dept. Agr. Year 
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Eggs and their Uses as Food. C. F. Langworthy. Washington, 1901. 

Infants' and Invalids' Foods. Bull. 59, Laboratory of the Inland Rev- 
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The Use and Abuse of Food Preservatives. W. D. Bigelow. U. S. Dept. 
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The Composition of Commercial Food Preservatives. U. S. Dept. Agr. 
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The Use of Borax and Boric Acid as Food Preservatives. V. C. Vaughan 
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Conformation of Beef and Dairy Cattle. A. M. Soule. Washington, 

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Some Essentials in Beef Production. F. Curtiss. Washington, 1898. 
Breeds of Dairy Cattle. H. E. Alvord. Washington, 1S99. 
The Dairy Herd: Its Formation and Management. H. E. Alvord. 

Washington, 1897. 
The Feeding of Farm Animals. E. W. Allen. Washington, 1897. 
The Source of Milk Fat. W. H. Jordan and C. G. Jenter. N. Y. Agr. 

Exp. Station Bull. 132. 
The Food Source of Milk Fat with Studies on the Nutrition of Milch Cows. 

W. H. Jordan, C. G. Jenter, and F. D. Fuller. N. Y. Agr. Exp. 

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Testing Cows at the Farm. Wis. Exp. Station Bull. 75. 
Effect on Dairy Cows of Changing Milkers. Sixteenth Report Wis. Agr. 

Exp. Station. 
Effect of Unequal Intervals between Milkings. Delaware Agr. Exp. 

Station, Bull. 43. 
Variations in Milk of Individual Cows. Illinois Agr. Exp. Station Bull. 24. 
Food Cost of Producing Milk. New York. Agr. Exp. Station Bull. 89, 

new series ; 16th and 17th Reports Wisconsin Agr. Exp. Station. 
Dairy Development in the United States. H. E. Alvord. Sixteenth An. 

Report Bureau of Animal Industry, U. S. D. A. 
Dairy Products at the Paris Exposition of 1900. H. E. Alvord. U. S. 

Dept. Agr. Year Book, 1900. 

Milk: Its Nature and Composition. C. M. Aikman. London, 1899. 
Milk and its Products. H. H. Wing. New York, 1897. 



REFERENCES. 343 

Dairy Chemistry. H. D. Richmond. Philadelphia, 1S99. 

Industrial Organic Chemistry. S. P. Sadtler. Philadelphia, 1895. 

Testing Milk and Its Products. E. H. Farrington and F. W. Woll. Madi- 
son, Wis., 1900. 

Analysis of Milk and Milk Products. Henry Leffman and William Beam. 
Philadelphia, 1896. 

Methods of Analysis of the Association of Official Agricultural Chemists. 
Adopted November nth, 12th, and 14th, 1898. Washington, 1899. 

Provisional Methods for the Analysis of Foods Adopted by the Association 
of Official Agricultural Chemists, November i4th-i6th, 1901. Wash- 
ington, 1902. 

Methods for the Estimation of the Proteolytic Compounds Contained in 
Milk and Cheese. L. L. Van Slyke and E. B. Hart. Bulletin 215, New 
York Agr. Exp. Station (Geneva). 

A Comparison of Reagents for Milk Proteids, with some notes on the Kjel- 
dahl Method for Nitrogen Determination. Alfred Vivian. Sixteenth 
Report, Wisconsin Agr. Exp. Station. 

Estimation of the Total Solids in Milk from the per cent of Fat and the Spe- 
cific Gravity of the Milk. S. M. Babcock. Eighth Report Wisconsin 
Agr. Exp. Station. 

Enzymes in Milk. S. M. Babcock, H. L. Russell, and Alfred Vivian. 
Fourteenth and Fifteenth Reports Wisconsin Agr. Exp. Station. 

The Action of Proteolytic Ferments on Milk with Special Reference to 
Galactase, the Cheese-ripening Enzyme. S. M. Babcock, H. L. Rus- 
sell, A. Vivian, and E. G. Hastings. Sixteenth Report Wisconsin Agr. 
Exp. Station. 

Albumoses and Peptones in Milk and Cream. S. M. Babcock and H. L. 
Russell. Fourteenth Report Wisconsin Agr. Exp. Station. 

Acidity of Milk-Detection by Pepsin. S. M. Babcock, H. L. Russell, A. 
Vivian, and E. G. Hastings. Sixteenth Report Wisconsin Agr. Exp. 
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Effect of Lime on Milk. Farmers' Bull. 69, U. S. D. Agr. 

Effect of Separator on Removing Dirt and Bacteria from Milk. S. M. 
Babcock. Eleventh Report Wisconsin Agr. Exp. Station. 

Creaming Experiments. S. M. Babcock. Eighth Report Wisconsin Agr. 
Exp. Station. 

Pasteurization of Milk and Cream at 140" F. E. H. Farrington and H. L. 
Russell. Sixteenth Report Wisconsin Agr. Exp. Station. 

Analyses of Milk and Whey. L. L. Van Slyke. New York Agr. Exp. 
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A Study of Some of the Salts formed by Casein and Paracasein with Acids. 
Their relations to American Cheddar Cheese. L. L. Van Slyke and E. 
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Chemical Changes in the Souring of Milk and their Relations to Cottage 
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Outlines of Dairy Bacteriology. H. L. Russell. Madison, Wis., iN'jy. 



344 REFERENCES. 

Agricultural Bacteriology. H. W. Conn. Philadelphia, 1901. 

Classification of Dairy Bacteria. H. W. Conn. Storr's Agr. Exp. Station 
Report. 1S99. 

The Ripening of Cream. H. W. Conn and W. M. Esten. Storr's Agr. 
Exp. Station Report, 1900. 

An Improved Curd Test for the Detection of Tainted Milks. S. M. Bab- 
cock. H. L. Russell, and J. W. Decker. Fifteenth Report Wisconsin 
Agr. Exp. Station. 

Some Comparative Examinations of Breast Milk and Cow's Milk, and the 
Effect of the Addition of Alkalies and Other Antacids to Cow's Milk. 
C. G. Kerley, A. H. Gieschen, and G. T. Myers. Medical Record, 
August 8th, 1903. 

Some Points in the Chemistry of Cow's Milk with Reference to Infant Feed- 
ing: with a description of a method of Home Modification of Cow's 
Milk. E. H. Bartley. Brooklyn Medical Journal, May, 1900. 

Scientific Modification of Milk. Thompson S. Westcott. International 
Clinics, October, 1900. 

A Method for the Differential Modification of the Proteids in Percentage 
Milk Mixtures. Thompson S. Westcott. The American Journal of the 
Medical Sciences. October, 1901. 

Whey and Cream Modifications in Infant Feeding. Franklin W. White 
and Maynard Ladd. Phila. Med. Jour., February 2d, 1901. 

The P^eeding Value of Whey. \V. A. Henry. Eighth Report Wisconsin 
Agr. Exp. Station. 

The Importance of Milk Analysis in Infant Feeding. A. H. Wentworth. 
Boston Medical and Surgical Journal, June 26th and July 3d, 1902. 

A Plea for the Conservation of Breast Milk in Whole or in Part. T. S. 
Southworth. Medical Record, May 4th, 1901. 

The Modification of Breast Milk by Maternal Diet and Hygiene. T. S. 
Southworth. Medical Record, April 26th, 1902. 

The Ambulatory and Hospital Management of the Gastro-intestinal De- 
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1900. 

The Treatment of Summer Diarrhoea in Infants. C. G. Kerley. Medical 
News, August 4th, 1900. 

A Study of Five Hundred and Fifty-five Cases of Summer Diarrhoea among 
the Out-Patient Poor. C. G. Kerley. Archives of Pediatrics, August, 
1901. 

A Clinical Study of Sixty-two Cases of Intestinal Infection by the Bacillus 
Dysenteriae (Shiga) in Infants. L. E. Le Fetra and John Howland. 
Archives of Pediatrics, March, 1904. 

Pediatrics. T. M. Rotch. Philadelphia, 1896. 

Diseases of Infancy and Childhood. L. E. Holt. New York, 1897. 

Craniometry and Cephalometry in Relation to Idiocy and Imbecility. Frede- 
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The Baby : His Care and Training. Marianna Wheeler. New York, 1901. 

The Destiny of Man. John Fiske. Boston, 1890. 



INDEX 



Absorption of food, 34 

Acidity of milk, 70, 142, 236, 237 

Albumin, 12, 39 

in milk, 48, 51, 75 
Albuminoid, 25 
Albumoses, 32 

in milk, 52, 75 
Animal cell, 10 

Babcqck milk test, 133 
Baby food warmer, 259 
Bacteria, 87 

classification of, 88 

counting, in milk, 98, 166-168 

decomposition, 91, 158 

differentiation of types of, 156 

food of, 89 

in dust, 95, 10 1 

in manure, 92 

in milk, 86, 117 

in soil, 92 

lactic, 90, 157, 266, 295 

numbers of, in certified milk, 
118 

numbers of, in grocery milk, 120 

numbers of, in milk, 117 

on cow's body, 95 

peptonizing, 91 

poisons produced by, 91, 15S 

rate of growth of, 89, 97, 98 
Bacteriological examination of 
milk, 86, 148, 295 

examination of milk, value of, 

l S 2 
Bacteriology of milk, 86, 14S 
Barley, 173, 182, 247 
gruel, 247, 252 



Barley gruel, dextrinized, 252 

Beans, 174 

Beef extract, 186 

juice, 184, 277 

pulp, 183 

scraped, 183 

tea, 186, 277 
Biscuits, analyses of, 178 
Bottle brush, 260 

filler, 114 

sterilizer, 119 
Bottled milk, 114, 223 

milk, advantages of, 225 
Bowel washing, 301 
Bread, 176, 178 

changes of flour in making, 176 

Graham, 178 

temperature of baking, 17S 

whole wheat, 178 
Breakfast foods, 173 
Breast, care of, 195 

feeding, 195 

feeding, contraindications for, 
199 

milk, separation of proteids of, 
142 

milk, reaction of, 145, 237 

pump, 200 

shield, 199 
Broths, chicken, mutton, and veal, 
187, 277 

Calipers, 325 
Calorie, 208 
Cane sugar, 26 
Carbohydrates, 26 
as fuel, 39, 20S 



346 



INDEX. 



Carbohydrates, effect on proteid 
metabolism, 38, 39 

estimation of, 27 
Casein, 12, 44 

to albumin, ratio of, in milk, 72 
Caseinogen, 4S 
Cellulose, 14. 26, 30, 170 
Cereals, 1 70 

analyses of, 173 

ci m iking of, 171, t 74 
Cereo, 239, 252 
Cereo gruel flours, 247 
Certified milk, 1 1 1 

milk, bacteria in, 1 17 

milk, cost of producing, 121 
Clarified milk, 105 
Colic, 27S 
Colostrum, 63, 212, 213 

function of, 211, 215 
Condensed milk, 82, 84, 180, 248, 271 
Constipation. 288 
Cooler, milk, 1 16 
Crackers, analyses of, 178 
Cream, 77 

albuminoid, 82, 103 

and milk mixtures, 223 

centrifugal, 78, 70 

centrifugal, separation of pro- 
teids in, Si 

difference between centrifugal 
and gravity, 78, 81 

evaporated, 83 

gravity, 77, 227 

gravity, composition of, 227 

separating, 77 

separator, So 

thickeners, 82 

time required for, to rise, 78, 
229 
Creamery, 113 
Curd test, 295 

Decay, 91 

Decomposition, 91, 158 
Deming's percentage milk modi- 
fier, 264 



Development of infants, 311 
Dextrin, 32,35, 175, 240 
Dextrinized gruels, 238, 252 

gruels, advantage of, as di- 
luents, 238 

gruels with eggs, 276 
Diarrhoea, summer, 293 
Diarrhceal diseases and milk supply, 

151. 293 
Diastase, 175, 239 
Diet, balanced, 40 

during second year, 303 

of nursing mother, 196 

selection of, 208 
Digestion, chemical process of, 29 

energy or labor expended in, 34 

how human, differs from that 
of lower animals, 31 

in different animals, 29 

mechanical process of, 1 7 

object of, 16 

tests, 28 
Digestive juices, 7,7, 

juices, secretion of, ^^ 

tract, development of, by milk, 
22, 24, 50, 58, 211 

tract, human, 23 

tract of cow, 19 

tract of dog, 18 

tract of horse, 21 
Diluents, 236, 251 
Diphtheria and milk supply, 15a 
Dipper for removing top milk, 550 
Drugs eliminated in milk, 198 
Dust, bacterial spores in, 10 1 
Dysentery bacillus, 298 

Eggs, 13, 188 

candled, 191 

composition of, 1S9 

flavor of, 190 

market grades of, 190 

preservation of, 191 
Egg-water, 277 

and dextrinized gruel, 276 
Enzymes, 31 



INDEX. 



347 



Enzymes act by contact, 33 
Enzymes in milk, 52 

of translocation, 35 
Evaporated creams, 83 
Excretion, 36 

by kidneys, 36, 300 

by lungs, 36, 300 
Extract of beef, 186 
Extractives, 13, 185, 302 

Fats, 26 

as fuel, 36, 208 

as proteid sparers, 39 

effect on appetite and diges- 
tion, 32, 34, 280 

estimation of, 2 7 

globules in milk, 67 

metabolism of, 36 
Fecal matter, 41, 268 

matter, a secretion, 41 

matter, character of depends on 
food, 41 

matter, color of, 42 
Feeding, adult, 208 

infant, 206 

infant, artificial, 250-280 

infant, breast, 195 

infant, by gavage, 281 

infant, key to percentage, 261 

infant, mixed, 202 

infant, nasal, 281 

infant, percentage, method of, 
218, 261, 263 

infant, premature, 285 

infant, rectal, 283 

infant, regularity necessary in, 
196 
Fibrin, 39 
Filtered milk, 106 
Flour, baked, 176 

ball, 175 

ball, changes in, 176 
Foetuses, comparison of, 57 
Fontanel, 334, 340 
Food, classification of, 25 

function of, 36 



Food, infant, condensed milk as, 
221, 248, 271 
infant, cream and milk mix- 
tures as, 223 
infant, effect of low protein in, 

220 
infant, for temporary use, 267 
infant, pasteurization of, 255 
infant, percentage composition 

of, 262, 264 
infant preparation of, 2 50-2 So 
infant, proprietary, 179 
infant, selection of, 250-280 
infant, sterilization of, 257 
infant, top milk mixtures as, 

250 
infant, warming of, 259 
infant, whey and cream mix- 
tures as, 272 
methods of selecting for adults, 

206 • 
methods of selecting for adults 
not applicable to infants, 206 
of different animals, 16, 31 
Formaldehyde in milk, 103, 105 
Fruit tablets, 291 

Gastric juice, action on meat, 32, 
1 S 4 
juice, secretion of, 33, 34 
Gelatin, 39, 18S 
Globulins, 12 
Glucose, 26 
Gluten, 14, 173, 177 
Glycogen, 13, 35,38 
Growth, a process of cell division, 
1 1 
of infants, 311 
of infant's head, 332 
Gruels, 233 

composition of ordinary, 246 
composition of standardized, 

246 
dextrinized, 238, 252 
Gruels, dextrinized, advantages of, 
as diluents, 238 



348 



INDEX. 



Hominy, analysis of, 



173 



Ice in Chicago, 107 

in London, 107 

in New York, 107 

in Paris, 107 
Infant foods and feeding, see Foods 
and Feeding. 

rudiment of parent, 15 

Junket, 20 

tablets, 71, 274 

Lactalbumin, 45 
Lactometer, 138 
Lecithin, 13, 51, 65, 222 
Legal standards for milk, 140 
Lime, effect on milk, 82, 237 
water, 14.3, 236, 258 

Maltose, 32, 35, 175 
Mammary foetus, 54, 56, 214 
Massage of bowel, 291 
Measurements of infants, 324 
Measuring board, 326 
Meat bases, 13, 187, 277 

broths, 187, 277 

extracts, 185 
Meats, 183 
Meconium, 41 
Metabolism, 36 

in adults, 38 

in infants, 38 

in starvation, 38 

of carbohydrates, 36 

of fats, 36 

of proteids, 36 
Milk, acidity of , 70, 142 

acidity of, detection by pepsin, 
70 

analyses of, 47, 49, 64, 68, 73 

analysis of, 45 

ass', 22, 47 

at Paris Exposition in 1900,108 

average, 47 

bacteriology of, 86 



Milk, bottled, 114, 225 

certified, 111 

certified, bacteria in, 118 

certified, bacterial standard 
for, 131 

certified, cost of producing, 119. 

clarified, 105 

classification of, according to- 
curding properties, 48 

commissions, in 

commissions, regulations, 124 

comparison of, 49 

condensed, 82, 84, 180, 248, 
271 

cow's, 22, 47, 53, 63 

curding of, object of, 20 

difference between acid and. 
rennet curds of, 48, 69 

enzymes in, 52 

fat of, 45 

filtered, 105 

fresh cow's, not truly acid, 69 
goat's, 22, 47, 53 
grocery, 112, 120 
grocery, bacteria in, 120 
grocery, cost of producing, 12 1 
inspected, 128 
inspected, bacteria in, 131 
laboratories, 266 
lecithin in, 51, 222 
legal standards for, 140 
mare's, 22,47, 53 
market, 1 10 
methods of testing, 133 
microscopic appearance of, j& 
mixed, of several cows, 72 
mixed, of several cows, analy- 
ses of, 73 
modification, key to, 262 
modifier, Deming's, 264 
of different animals, 47, 49 
one cow's, 65 
one cow's, effect of irregular 

hours of milking, 68 
one cow's, fractional milkings, 
66 



INDEX. 



349 



Milk, one cow's, variations in, 68 
pasteurized, ioo, 107, 255 
peptonized, 275 
physiological function of, 22, 

24, 211 
preservation of, 100 
preservation of samples, 147 
preservatives, 100, 146 
production in Europe, 108 
proteidsof, 43, 53, 75 
receiving stations, 113 
sheep's, 22, 47, 53 
souring of, 69, 90 
specific gravity of, 136 
sterilized, 100 
sterilized, detection of, 147 
sugar of, 44 
top, 227, 230, 268, 269 
woman's, 22, 47, 53 
woman's, examination of, 202 
woman's, modification of, 202 
woman's, ratio of fat to pro- 

teids in, 224 
woman's, reaction of, 145, 237 

Mineral matter, estimation of, 46 
matter in food, 25, 27 
matter in milk, 46, 61 

Nipple, 259-261 

care of, 195 

shield, 199 
Nitrogenous equilibrium, 37 
Nucleo-albumin, 12 
Nursery stove, 261 
Nursing, 195 

contraindications for, 199 

hours for, 196, 253 

wet, 200 
Nursing-bottles, 254 
Nutritive ratio, 209 

Oatmeal, 173 
gruel, 246 
gruel, dextrinized, 252 

Paracasein, 69, 213 
Pasteurization of milk, 100, 107, 255 



Pasteurization of milk in Europe, 

102, 107, 108 
Peas, 173 
Peptones, 32 

in milk, 52, 73, 75 
Peptonized milk, 275 
Percentage feeding, 218, 261, 263 

feeding, key to, 261 
Premature infants, 285 
Preservatives, food, 102 

in milk, 146 
Proteid, 25 
Protein, 12, 25 

all animals must have, 16 

animals cannot elaborate, 15 

decomposition of, 9 1 

effect of diet, high and low in, 
220 

estimation of, 27 

forms of, 12, 39 

forms of, in milk, 43, 51, 53, 75 

kind of, required in food, 39 

metabolism of, 36 

metabolism of, effect of carbo- 
hydrates on, 38 

plants can elaborate, 15 

quantity of, required in food, 
40 

vegetable, 14, 170 
Prunes, 290 
Putrefaction, 91 

Refrigerators, temperature of, 

25S 
Rennet, 20 

function of, 20, 49 
Rice, 173 

gruels, 252 

mould, 175 
Rumen, iS 

Scales, grocer's, 312 

Scarlet fever and milk supply, 150 

Separator, cream, 80 

Shiga bacillus, 298 

Skull outline of infants, 334-337 



ay 



INDEX. 



eparator, 80 

Slimy milk, 92 

Sodium bicarbonate, 258 

citrate, 258 
Standardized gruels, 246 
Starch, 26, 171 

bursting of grains by cooking, 
174 

in bread, 176 
Starvation, 37 

in children, 38 

effect of albumen in, 39 

effect of carbohydrates in, 3S 

effect of proteid in, 39 
Sterilization of milk, 100, 257 
Sterilizers, 119, 256 
Stomach of different animals, 16-24, 
53 

tube, 282 

washing, 282 
Stools, infants', 41, 268 
Streptococci in milk, 94, 159 
Sugar, 26 

cane, 26 

effect on digestion, 34, 2 So 

estimation of, 47 

milk, 26, 44 

milk, of cows not identical 
with human, 44 
Summer diarrhoea, 293 

diarrhoea and milk supply, 151, 
294 
Suppositories, 284, 285 



Teething, 



3i5 



Thickeners, cream, 81 
Tin pudding bag, 175 
Top milk, 218, 236 

milk mixtures, 253 
Tuberculin test, 95 
Tuberculosis and milk supply, 95, 

148 
Tuberculous udder, 94 
Typhoid fever and milk supply, 149 

Udder, cow's, q2 

tuberculous, 94 
Urea, 36, 300 
Uric acid, 36 
Urine, 36, 40, 300 
Utensils, seams of dairy, 96 

Vegetable foods, 170 
Viscogen, 81 
Vomiting, 278 

Weaning, 202 

Weight chart, 313 

infant, 3 13 
AVet-nursing, 200 
Wheat bread, 178 

breakfast foods, 173 

flour, 180 

flour gruels, 246, 252 

flour gruels, dextrinized, 246, 
252 
Whey, 49, 72, 73 

analyses, of, 73 

and cream mixtures, 272 

to make, 274 

food value of, 2 74 



FEB 25 1909 



